phylum arthropoda subphylum crustacea brünnich, 1772

9

SYSTEMATIC LIST OF INDIAN DIAPTOMID SPECIES

Phylum Arthropoda

Subphylum Crustacea Brünnich, 1772

Class Maxillopoda Dahl, 1956

Subclass Copepoda Milne Edwards, 1840

Order Calanoida Sars, 1903

Family Diaptomidae Sars, 1892

Subfamily Paradiaptominae Kiefer, 1932

I. Genus Paradiaptomus Sars, 1895

1. Paradiaptomus greeni (Gurney, 1906)

Subfamily Diaptominae Kiefer, 1932

VI. Genus Tropodiaptomus Kiefer, 1932

2. Tropodiaptomus defayeae n.sp.

3. Tropodiaptomus venkataramani n.sp.

4. Tropodiaptomus raoi n.sp.

5. Tropodiaptomus keralaensis n.sp.

6. Tropodiaptomus orientalis (Brady, 1886)

7. Tropodiaptomus doriai (Richard, 1897)

8. Tropodiaptomus hebereri Kiefer, 1930

9. Tropodiaptomus mutatus Kiefer, 1930

10. Tropodiaptomus vicinus Kiefer, 1930

11. Tropodiaptomus euchaetus Kiefer, 1936

II. Genus: Heliodiaptomus Kiefer, 1932

12. Heliodiaptomus viduus (Gurney, 1916)

13. Heliodiaptomus contortus (Gurney, 1907)

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14. Heliodiaptomus cinctus (Gurney, 1907)

15. Heliodiaptomus pulcher (Gurney, 1907)

16. Heliodiaptomus kolleruensis Ranga Reddy & Radhakrishna, 1981

17. Heliodiaptomus elegans Kiefer, 1935

III. Genus Allodiaptomus Kiefer, 1936

18. Allodiaptomus (Allodiaptomus) mirabilipes Kiefer, 1936

19. Allodiaptomus (Allodiaptomus) intermedius Ranga Reddy, 1987

20. Allodiaptomus (Allodiaptomus) satanas (Brehm, 1952)

21. Allodiaptomus (Reductodiatpomus) raoi Kiefer, 1936

IV. Genus Neodiaptomus Kiefer, 1932

22. Neodiaptomus schmackeri (Poppe & Richard, 1892)

23. Neodiaptomus lindbergi Brehm, 1951

24. Neodiaptomus physalipus Kiefer, 1935

25. Neodiaptomus intermedius Flößner, 1984

26. Neodiaptomus meggitti Kiefer, 1932

V. Genus Phyllodiaptomus Kiefer, 1936

27. Phyllodiaptomus (Phyllodiaptomus) blanci (Guerne & Richard, 1896)

28. Phyllodiaptomus (Ctenodiaptomus) wellekensae Dumont & Ranga Reddy, 1993

29. Phyllodiaptomus (Ctenodiaptomus) annae (Apstein, 1907)

30. Phyllodiaptomus (Ctenodiaptomus) sasikumari Ranga Reddy & Venkateswarlu, 1989

VII. Genus Sinodiaptomus Kiefer, 1936

31. Sinodiaptomus (Rhinediaptomus) indicus Kiefer, 1936

32. Sinodiaptomus (Rhinediaptomus) mahanandiensis Ranga Reddy & Radhakrishna, 1980

VIII. Genus Megadiaptomus Kiefer, 1936

33. Megadiaptomus pseudohebes Ranga Reddy, 1987

34. Megadiaptomus hebes Kiefer, 1936

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IX. Genus Eodiaptomus Kiefer, 1932

35. Eodiaptomus shihi Ranga Reddy, 1992

X. Genus Spicodiaptomus Rajendran, 1973

36. Spicodiaptomus chelospinus Rajendran, 1973

X1. Genus Keraladiaptomus Silva, Kakkassery, Maas & Dumont, 1994

37. Keraladiaptomus rangareddyi Silva, Kakkassery, Maas & Dumont, 1994

X11. Genus Acanthodiaptomus Kiefer, 1932

38. Acanthodiaptomus denticornis (Wierzejski, 1887)

XIII. Genus Arctodiaptomus Kiefer, 1932

39. Arctodiaptomus (Arctodiaptomus) similis similis (Baird, 1859)

40. Arctodiaptomus (Arctodiaptomus) eucanthus Kiefer, 1935

41. Arctodiaptomus (Rhabdodiaptomus) salinus (Daday, 1885)

42. Arctodiaptomus (Rhabdodiaptomus) michaeli Ranga Reddy, Balkhi& Yousuf, 1990

43. Arctodiaptomus (Stenodiaptomus) stewartianus (Brehm, 1924)

44. Arctodiaptomus (Stenodiaptomus) altissimus altissimus Kiefer, 1936

45. Arctodiaptomus (Haplodiaptomus) parvispineusKiefer, 1935

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Subfamily Paradiaptominae Kiefer, 1932

Genus Paradiaptomus Sars, 1895

Broteas: Lovén, 1845 (partim)

Paradiaptomus: Sars, 1895

Broteas: Gurne & Richard, 1890: 200 (partim); Sars, 1899: 4.

Paradiaptomus: Giesbrecht & Schmiel, 1898: 95; Sars, 1907: 3; Tollinger, 1911: 187; van

Douwe, 1912a: 2; 1912b: 25; 1914: 96; Gurney, 1929: 572; Lowndes, 1936: 5; Kiefer, 1932a:

462; Kiefer, 1934: 123; Kiefer, 1978: 75; Defaye, 1988: 112; Dussart, 1989: 28; Rayner, 1992:

36-39; Dussart & Defaye, 1995: 124; Defaye et al., 200: 247-248; Dussart & Defaye, 2002: 64.

Lovenula: Grochmalicki, 1913: 525.

Generic diagnosis

Animals large (total length c. 2.0-2.5 mm). Antennule short, barely reaching the end of

prosome. Female: Fourth and fifth pedigers fused; urosome of 2 somites, genital double-somite

with asymmetrical lobes; P5 endopod with 2 spiniform setae. Male: Right antennule 21-

segmented, only 3 segments (exception: 4 segments in P. greeni) beyond geniculation, last

segment ending in a beak or rounded terminally; outermost seta of right caudal ramus enlarged;

right P5 with 1 disto-lateral spine; left P5 with sturdy lateral spiniform process on second

exopodal segment.

Type species: Paradiaptomus lamellatus Sars, 1895

Other valid species:

Paradiaptomus natalensis (Cooper, 1906)

Paradiaptomus greeni (Gurney, 1906)

Paradiaptomus schultzei van Douwe, 1912

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Paradiaptomus similis van Douwe, 1912

Paradiaptomus rex Gauthier, 1951

Paradiaptomus hameri Rayner, 1999

Paradiaptomus peninsularis Rayner, 1999

Paradiaptomus warreni Rayner, 1999

Of the above species, P. greeni is the sole representative in India.

Paradiaptomus greeni (Gurney, 1906)

(Figs 1-4, Pl. 5)

Diaptomus greeni Gurney, 1906: 129-132, P1. 2, Figs 1-9; Tollinger, 1911: 119, Fig. F3.

Paradiaptomus similis van Douwe, 1912: 21-32, P1. IV, Figs 13-14.

Paradiaptomu greeni Gurney, 1931: 301-303, Figs 1-5; Kiefer, 1934:12, Figs 33-35; Kiefer,

1939: 92-95, Figs 1a-i; Brehm, 1950: 15; Brehm, 1953: 298-302, Figs 60-64; Rajendran,

1973:120-121, Figs 6 a-i; 141-161: Dussart & Defaye, 2002: 65; Ambedkar, 2005: 20-23, Figs 1-

8.

Type locality

Muddy stagnant pool, Cotton Experiment Station, Maha Ilupalama, North-Central

Province of Sri Lanka.

Material examined: as in Table 02.

Body size. Female 2.03-2.62 mm; male 1.86-2.13 mm.

Female

Body stout, fourth and fifth pedigers fused together, fusion indicated by indentation on

either side. Lateral wings of fifth pediger asymmetrical, large and somewhat ovate; left wing

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smaller than right wing, posterolaterally directed; each wing armed with 1 apical and 1 inner

spine.

Urosome of 2 somites, second urosomite being fused to anal somite; sometimes

vague present septum separating the latte 2 segments; genital double-somite prominently

expanded in anterior half, with large bifid lobe on right side and small hook-like process on left

side. Second urosomite (urosomite 2 + anal somite) half as long as genital double-somite. Caudal

rami slightly asymmetrical, right ramus being somewhat narrower than left; inner margins hairy.

P5 (Fig. 1g-j, Pl. 5c). Coxal spine small. Seta on basis small. End claw (exopod 2)

moderately strong and blunt, carrying along inner margin a row of minute denticles; lateral spine

highly variable in size (Figs 1d, 1 e, Pl. 5 b). Exopod 3 small and with 2 unequal spines, outer

one being longer and stronger than inner one. Endopod unsegmented, somewhat shorter than

exopod1; apex with two unequal spines.

Male (Figs 2, 3). Metasomal wings greatly reduced, asymmetrical, right wing slightly

narrower than right one .

Caudal rami asymmetrical with hairy inner margins. All caudal setae of left ramus as well

as 4 inner setae of the right ramus normal, outer seta of the right ramus modified (Fig. 2a, Pl. 5d).

Antennule (Figs 2c, 3d-e). Left antennule as in female, right antennule modified and

geniculate; distal part beyond geniculation 4-segmented; with spine on segments 8 and 10-13;

length of spines in decreasing order as follows: 11>13>10>8>12; spine on segment 13 strong;

terminal segment beaked (Pl. 5e, f)

Right P5 (Figs 2d-i, 3f-m, Pl. 5g-i). Coxa with short, slender, acute spine; basis with

short sensory seta. Exopod 1 with dome-shaped blunt spine spine at distal outer angle; shape of

spine slightly variable (Figs 2e, 3h); distal inner corner with thumb-shaped hyaline lobe; exopod

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2 very strong, almost rectangular, 1.8 times as long as wide; lateral spine inserted close to end

claw on posterior surface; end claw with serulations on inner margin. Endopod 2- segmented,

proximal segment larger; distal segment with a row of apical tiny spinules. Left P5: coxa with

slender spine; basis with small sensory seta; exopod 2 extended as a flange fringed with minute

spinules and armed laterally with a slender spine and slender seta.

Remarks

The following characters have been observed to show intraspecific variation: in the

female, the size of outer spine on left wing; lateral processes on genital double-somite, size of

lateral spine on second exopodal segment, and segmentation and apical spines of endopod of P5;

in the male right P5, the spinous process at distal outer corner and the hyaline projection at distal

inner corner of the first exopodal segment, the size and orientation of the lateral spine of second

exopodal segment, the form of end claw and segmentation of endopod.

P. greeni was reported by Gurney (1931) as being common to Sri Lanka, India and South

Africa. However, Rayner (1999), while revising the subfamily Paradiaptominae, reportedly

confirmed on the basis of material from India and Namibia that Gurney (1931) mistook P. greeni

for P. similis, an African species occurring in Kalahari, Namibia and other part of Africal.

Rayner (1999) also called attention to the subtle differences between these two species in the

male P5 and length and arrangement of spines on grasping antennule. Having examined the

permanent slide preparation of both sexes of P. similis from South Africa and compared this

species with several populations of P. greeni from India and Pakistan, I agree Rayners‘ (1999)

view that these two species are distinct from each other (Table 2).

Colour

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The caudal setae as well as the terminal segments of antennule are brightly pink in both

sexes.

Ecology

P. greeni appears mainly during early monsoon period (June-August) in highly turbid

or moderately transparent, shallow, temporary, fishless water bodies such as seasonal ponds

and pools in which water temperature ranges from 19º to 29ºC and pH 7.0-7.5 and Secchi

transparency 39-40 cm. It often co-occurs with H. viduus, P. blanci and S. indicus. This species

is amenable to cultivation under laboratory conditions. According to Devi & Ranga Reddy

(1989a), who raised it from its eggs, it completes naupliar phase in 3 days and copepodid phase

in 6 days at a room temperature of 28º- 36º C.

Distribution

Previous records

This species has a widely distributed in Sri Lanka (Ceylon) and India. In India it has

been reported from Madurai, Nellore, Gooty, Guntakal, Dharamavaram, Nambur, Nellore,

Phandharpour, Soharva, and Kodaikanal.

Present records

Nallapadu, Vejendla, Akaveedu and Cumbum—all in the State of Andhra Pradesh.

Conservation Status: LR.

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Subfamily Diaptominae Kiefer, 1932

Genus Tropodiaptomus Kiefer, 1932

This genus has two subgenera, viz. Tropodiaptomus s. str. and Anadiaptomus. The latter was

established by Brehm (1952) for only two Madagascan species whereas all other species belong

to the former. In India, the genus has been poorly studied.

Generic diagnosis

Female: urosome composed of 2 somites. Endopod with 1 subapical and 1 apical seta. Male:

right antennule with spine each on segments 8, 10, 11, 12, 13 and 15; segment 14 without spine;

spinous process on antepenultimate segment is always smooth. Left P5 exopod 1-segmented,

spatulate; apex rounded with spinulate seta (finger-thumb-process) and inner margin with

serulate or denticulate. Second exopodal segment of right P5 with hyaline lamella or spine near

the base of lateral spine.

Initially, Brehm (1953) provided a brief review of the Indian species along with an

identification key. The principal revisionary work on the Asiatic species of this genus is that of

Kiefer (1982). And according to Dussart & Defaye (2002), the genus contains t 64 species, most

of which are distributed in Africa and Asia. In India, the genus is represented by the following 14

species including three new species besides one new Nepalese species.

Type species: Tropodiaptomus orientalis (Brady, 1886)


Tropodiaptomus doriai (Richard, 1897)

Tropodiaptomus hebereri (Kiefer, 1930)

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Tropodiaptomus mutatus (Kiefer, 1930)

Tropodiaptomus vicinus (Kiefer, 1930)

Tropodiaptomus euchaetus Kiefer, 1936

Tropodiaptomus signatus Kiefer, 1982

Tropodiaptomus defayeae n. sp.

Tropodiaptomus keralaensis n. sp.

Tropodiaptomus raoi n. sp

Tropodiaptomus venkataramani n. sp.

Species incertae sedis:

Tropodiaptomus nielseni Brehm, 1953

Tropodiaptomus lakhimpurensis Reddiah, 1964

Tropodiaptomus chauhani Roy, 1984

Key to female Indian Tropodiaptomus spp.

1. Fourth seta (counted from outside) of third exopodal segment of P4 extraordinarily

long……………………………………………………………………………T. orientalis

The same normal…………………………………………………………………………..2

2. Genital double-somite with large swelling on subproximal left margin

………………………………………………………………………………..…T. signatus

No such structure…………………………………………………………………………….3

3. Fifth pediger with roundish hump mid-dorsally………………………..………T. hebereri

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No such structures………………………………………………………………………..4

4. Genital double-somite dilated alike on both sides subproximally; setae on P5 endopod

always short………………………………………………………………………T. doriai

Genital double-somite not dilated on both sides sub proximally; setae on P5 endopod

either short or long……………………………..…………………………………………5

5. Genital double-somite produced into small lobe at right distal corner……………….....6

No such structure………………………………………………………………………….7

6. P5 endopod setae sturdy and spiniform; coxal spine large………………T. defayeae n. sp.

P5 endopod setae slender and setiform; coxal spine small……………………T. raoi n. sp.

7. On P5 endopod, apical seta as long as or longer than endopod……………………………8

On P5 endopod, apical seta shorter than endopod………………………………………10

8. P5 basis seta long; apical endopodal seta naked……………………….T. keralaensis n. sp.

P5 basis seta short; apical endopodal seta pinnate………………………………………….9

9. P5 endopod as long as inner margin of first exopodal segment……T. venkataramani n. sp.

P5 endopod shorter than first exopodal segment…………...………………….T. euchaetus

10. Female caudal rami with hairy outer margins; genital genital double-somite nearly

symmetrical ……………………………..………………………………………T. vicinus

Female caudal rami with hairless outer margins; genital double-somite decisively

asymmetrical…………………………………………………………………..T. mutatus

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Key to the male Indian Tropodiaptomus spp.

1. Right P5 exopod 2 with short lateral spine…………………………………….T. signatus

The same long…………………………………………………………………………….2

2. Left P5 exopod with partly dentate inner margin……………………………….T. hebereri

Left P5 exopod with uniformly serrulate inner margin…………………………………...3

3. Right P5 exopod 2 with long setiform accessory process; spinous process on segment 13

of right antennules serrate on inner margin…………………………………...T. euchaetus

Right P5 exopod 2 with lobe-like accessory process; spinous process on segment 13 of

right antennules normal…………………………………………………………………4

4. Left P5 exopod saw bilobed…………………………………………………………...5

Left P5 exopod saw unilobed……………………………………………………6

5. Right and left P5 basis short; spinous process on segment 15 and antepenultimate

segment right antennule short……………………………………………………T. doriai

Right and left P5 basis long; spinous process on segment 15 and antepenultimate segment

long………………………………………………………………………………T. vicinus

6. Right P5 basis with 2 hyaline lobes; left P5 endopod and spinous process on segment 13,

15 and antepenultimate segment long…………………………………………T. mutatus

Right P5 basis with 3 hyaline lobes; left endopod and spinous process on segment 13, 15

and antepenultimate segment long……………………………………………T. orientalis

7. Right P5 exopod 2 stumpy with lateral spine lying opposite to end claw almost at the

same level; segment 1 of right antennule with accessory hyaline

process…………………………………………………………….T. venkataramani n. sp.

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Right P5 exopod 2 elongate, with lateral spine lying distinctly proximal to end claw;

segment 13 of right antennules without accessory process………………………………8

8. Right P5 exopod 2 distinctly narrow beyond to level of lateral spine; exopod 1 with

prominent hyaline process at inner distal corner; left P5 exopod narrow

distally…………………………………………………………………T. keralaensis n. sp.

Right P5 exopod 2 normal beyond lateral spine; exopod 1 with or without short hyaline

process at inner distal corner; left P5 exopod broad distally…………………………….9

9. Right P5 asis stumpy; spinous process on segment 13 and antepenultimate segment short;

left P5 basis with hyaline lobe ………………………………………..…T. defayeae n. sp.

Right P5 basis elongate; the said spinous process long; left P5 basis without hyaline

lobe……………………………………………………………………………T. raoi n. sp.

Tropodiaptomus orientalis (Brady, 1886)

(Figs 5-7, Pl. 6)

Diaptomus orientalis: Brady, 1886.

Tropodiaptomus informis Kiefer, 1936e: 81-82, Figs 12-14; 1982: 246, Figs 12a-n; Brehm,

1953: 293-294 ; Devi & Ranga Reddy, 1990a: 55-75.

Tropodiaptomus australis, non Kiefer, Fernando, 1980.

Tropodiaptomus orientalis: Dussart & Fernando, 1985: 235, Figs 22-27; Dussart et al., 1984;

Dusart, 1989a, 1989b; Dussart & Defaye, 2002: 136.

?Tropodiaptomus sp. (prope orientalis (Sars) Dumont & Maas, 1988.


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Female (Fig. 5, Pl. 6a)

Total length exclusive of setae 1.3-2.0 mm, average length 1.6 mm (N = 7). Fourth and

fifth pedigers perfectly fused together without any lateral indentation; posterolateral wings of

fifth pediger large, nearly symmetrical and bilobed; outer apical spine larger than inner one.

Urosome of two somites. Genital double-somite 1.6 times longer than wide, with slight

dilation at midlength of right margin and armed with 2 tiny, equal dorsolateral spines lying

opposite to each other subproximally; in lateral view (Fig, 5b), incomplete septum discernible;

genital boss conspicuous, with genital opening facing posterolaterally. Caudal rami parallel,

symmetrical, 1.5 times as long as wide with hairy inner margins.

All cephalic appendages and P1-P4 as in T. defayeae n. sp. except fourth seta of third

exopodal segment of P4 being extraordinarily long (Fig. 5d, Pl. 6a).

P5 (Fig. 5f). Symmetrical. Coxa 1.2 times longer than wide and with a short acute

spinous process at inner distal corner. Basis wide with short, delicate sensory seta. First exopodal

segment 1.5 times longer than wide. Second exopodal segment tapering into a strong claw and

with spinulate outer and inner margins; lateral spine rudimentary. Third exopodal segment

partially fused to second segment, bearing short outer spinous process and long inner seta.

Endopod unisegmented, as long as first exopodal segment and with two strongly unequal setae;

apical seta about as long as endopod, with setules on outer distal margin; subapical seta less than

half as long as apical seta and naked; a pecten of spinules at the apex of endopod. No ovigerous

and spermatophore-bearing females were found in the present collections.

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Male (Figs. 6, 7, Pl. 6b-f).

Total length exclusive of setae 1.5 -1.8 mm, average length 1.5 mm (N = 7) Rostral

spines as in Fig. 6c. Fifth pediger produced into small, almost symmetrical, postero-lateral

wings, each wing with two tiny unequal spines, apical spine relatively large.

Urosome of 5 somites, attenuating but little behind and gradually bending to right side.

Genital somite indented on left side; right distal corner with fine sensillum; sensillum not easily

visible in all specimens. Fourth urosomite asymmetrical, right distal corner being produced into

short roughly triangular projection. Caudal rami symmetrical, each ramus 1.5 times as long as

wide with hairy inner margins.

Antennules extending up to genital somite. Left antennule as in female. Right

antennule (Fig. 6 d-f, Pl. 6b, c) with spine on each of segments 8 and 10-13, 15; relative length of

spines in decreasing order as follows: 13>15>11>10>8>12. Spinous process on antepenultimate

segment as long as next segment, blunt or produced into beak-like structure apically.

P5 (Fig. 7, Pl. 6d-f). Right P5: coxa longer than wide, proximal inner corner produced in

to a small lobe; a slender spine arising from a lobe near mid-caudal border; basis twice as long

as broad, rectangular in outline, inner margin with 2 unequal hyaline lobes, proximal one

distinctly smaller than distal one; 1 additional small, hyaline lobe on caudal surface close to

inner margin. Sensory seta slender, inserted near outer distalcorner. First exopodal segment

produced into short spinous process at outer distal corner and inner distal corner, as illustrated;

also, one small triangular hyaline outgrowth occurring close to outer distal spinous process.

Second exopodal segment twice as long as wide, with inconspicuous hyaline lobe on mid-inner

margin; lateral spine arising from distal third of second exopodal segment, about as long as

segment and serrulate on inner distal margin; a hyaline outgrowth in the form of moderately

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large spine lying near base of lateral spine on caudal surface; end claw 1.4 times as long as

second segment, distal half sharply bent inwards and finely serrulate. Endopod as long as first

exopodal segment, tapering towards apex; apex rounded with apical and subapical spinules. Left

P5 reaching up to first exopodal segment of right P5. Coxa with short hyaline spine arising from

a lobe-like structure. Basis roughly rectangular, nearly twice as long as long as wide with a

distinct hyaline lobe on inner distal margin and slender sensory seta at outer distal region.

Exopod nearly oval; distal half of inner distal margin finely serrulate; ending, as usual, in a

digitiform appendix paired with seta (‗finger-and-thumb‘); finger much slenderer than thumb

and beset with radiant, long spinular hairs. Endopod stout, vaguely 2-segmented and covering

proximal seta-cushion.

Remarks

One spectacular but non-conventional character that has hitherto been not documented

for T. orientalis is the presence of extraordinarily long seta (fourth one from outside) on the

third exopodal segment of P4; even the setules of this seta are quite large (Fig. 5d, Pl. 6a). All

the nine populations examined in the present study closely agree with Kifer‘s (1982) figures and

description of T. informis, now a synonym of T. orientalis, especially in various details of the

male: the hyaline outgrowths on the basis, the size and shape of the endopod and the second

exopodal segment of right P5; the presence of hyline lobe on the basis and the overall form and

the ornamentation of inner margin of the left P5; and the spinous process on antepenultimate

segment of grasping antennule. As pointed out by Kiefer (1982), the size and shape of the spines

on segments 10, 11, 13 and 15 of the grasping are variable. In the female, however, the genital

double-somite is somewhat shorter and the apical seta on P5 endopod longer. Compared with

Dussart & Fernando‘s (1985) account of this species, the Indian populations show some, perhaps

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minor, differences: in the female, the genital-double somite is relatively short, but P5 endopod

and its outer seta long. In the male, the only difference is that the right P5 basis is somewhat

stouter. On the whole, T. orientalis appears to be a variable species.

According to Devi & Ranga Reddy, 1990, who studied morphology of the postembryonic

stages of this species under laboratory conditions, the duration of the naupliar and copepodid

phases is 15 days. And the shape and number of setae on the terminal segments of the antennules

in the late naupliar stages and shape and setae of P5 exo- and endopod of copepodids III-V are

most useful in the identification of instars.

Ecology

T. orientalis appears mailnly during early monsoon period in highly turbid or

moderately transparent, shallow temporary, fishless water bodies such as seasonal ponds and

pools in which water temperature ranges from 19-29ºC and pH 7.5-8.5 and Secchi transparency

25-68 cm. This species is amenable to cultivation under laboratory conditions. According to

Devi & Ranga Reddy (1990a) who raised this species from its eggs, it completes naupliar phase

in 4 days and copepodid phase in 11 days at a room temperature of 30- 36Cº. It often co-occurs

with N. Schmackeri and S. indicus.

Distribution

Previous records: Mysore, Karaikal, Gauhati, Barni Hat in Khasi Hills, Lake Kolleru at

Kolletikota and Manuguluru, Ponnur, Hyderabad, Warangal, Lake Kondakarla at

Visakhapatnam. Belur in Karnataka State.

Present records: see Table 4.

Conservation Status: Lower Risk, near threatned (LR nt)

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Tropodiaptomus defayeae n. sp.

(Figs 8-14, Pls. 7, 8)

Type locality and Material examined

Temporary pond at Ankidha near Khatmandu (27° 42′ 0″ N, 85° 20′ 0″ E), Nepal. 2

females, 2 males.

Holotype adult male dissected on 4 slides, allotype adult female dissected on 6 slides,

paratype adult male mounted as whole specimen on a slide. Type material is kept in the

Department of Zoology, Acharya Nagarjuna Universiy, pending transfer to the Muséum national

d‘Histoire naturelle, Paris. Leg: M. K. Durga Prasad & U. Vasu.

Diagnosis

Male: on right antennnule, spinous process of 13th segment stout and without accessory

hyaline spine; spinous process of antepenultimate segment claw-like, shorter than next segment.

Right P5: basis somewhat oval, 1.4 times as long as wide with 2 small hyaline structures at

about the middle, proximal one, triangular, distal one membranous; a large thumb-like hyaline

lobe occurring close to subproximal inner margin on the anterior surface. First exopodal

segment produced into moderately long spinous process at outer distal corner; 1 accessory

hyaline lobe present near base of spinous process; inner distal corner produced into a small

triangular hyaline lobe. Second exopodal segment along with usual accessory spine and a small

hyaline button near mid-inner margin, lateral spine inserted at distal third, moderately strong, as

long as segment. Left P5: basis rectangular with one large, lamellate hyaline lobe on inner distal

margin. Exopod somewhat slender, saw with uniformly minute serrations with short radii.

Endopod unisegmented.

27

Female: distal outer corner of genital double-somite produced into small rounded lobe.

Left and right spines on genital double-somite tiny and directed posterolaterally. Inner margin of

caudal rami hairy. P5: endopod 0.6 times as long as first exopodal segment, setae transformed

into sturdy spines.

Description of adult female (Holotype) (Figs 8-11, Pls. 7a-d, 8a)

Total length exclusive of caudal setae 1.84 mm. Rostral spines as in Fig. 8b. Fourth and

fifth pedigers completely fused, fusion being indicated by indentation on each side. Fifth pediger

produced into asymmetrical posterolateral wings; left wing longer than right wing; each wing

bilobed and armed with 2 unequal spines, inner spine longer.

Urosome of 2 somites. Genital double-somite somewhat symmetrical, longer than anal

somite and caudal rami combined and produced into small rounded lobe at outer distal corner;

armed with 2 unequal dorsolateral spines (left spine slightly smaller than right spine) lying

opposite to each other subproximally. Anal somite slightly longer than caudal rami, proximal

third telescoped into genital double-somite, distally dilated and deeply cleft. Caudal rami

parallel, symmetrical, with hairy inner margins; each ramus 2.2 times as long as wide, lateral seta

much like other principal setae; dorsal jointed setae of both rami equal in length.

Antennule symmetrical (Fig. 8c), 25-segmented, extending beyond the tips of

caudal setae by last 2 or 3 segments. Armature of all cephalic appendages and swimming legs as

in T. defayeae n. sp.

P5 (Fig. 11, Pls. 7d, 8a). Coxa massive, roughly spherical in outer line, with

broadly triangular hyaline spine posteromedially and large hyaline spine posterolaterally. Basis

with short sensory seta. First exopodal segment 2.2 times as long as wide, with somewhat wavy,

convex outer margin and almost straight inner margin. Second exopodal segment with short

28

lateral spine. Third exopodal segment distinct; outer spine thick, acute and fused; inner seta

extending beyond midlength of the end claw. End claw with spinulose outer and inner margins.

Endopod unsegmented, 0.6 times as long as first exopodal segment and armed with 2 strong

unequal spiniform setae; outer seta apical in position and half as long as endopod; inner seta

subapical, 0.8 times as long as outer spine; a pecten of spinules at the base of either seta. (Fig.

11).

Ovigerous female (Pl. 8a) with large roughly spherical ovisac, containing 22 eggs.

Description of adult male (allotype) (Figs 12-14, Pls. 7e-h, 8b)

Total length exclusive of caudal setae 1.79 mm. Suture separating 4 and 5 pedigers

complete. Pediger 5 produced into small, almost symmetrical, triangular, posterolaterally-

directed wings; each wing with 2 small, unequal spines, apical spine relatively large.

Urosome of 5 somites, attenuating but little behind and gradually bending to right side.

Genital somite indented and without any sensillum at left caudal corner; right caudal corner

armed with one sensillum. Anal somite shortest, deeply cleft. Caudal rami symmetrical, longer

than wide with hairy inner margins; caudal setae normal.

Left antennule as in female. Right antennule as in Fig. 12b, Pl. 7f; size of spinous

processes as in Fig. 12d; segment 13 with stout spine and without accessory hyaline spine (Pl.

7f); antepenultimate segment shorter than next segment, with narrow hyaline membrane on outer

margin (Fig. 12 d, Pl. 7g).

Other cephalic appendages and swimming legs as in female.

Right P5 (Fig. 13a, Pls. 7e, h, 8b): coxa 1.2 times longer than wide and armed with

slender hyaline spine arising from a lobe-like structure. Basis somewhat oval, 1.4 times as long

as wide, inner margin convex, with 2 small hyaline structures at about midlength, proximal one

29

triangular, distal one membranous; a large thumb-like hyaline lobe occurring close to

subproximal inner margin on the frontal surface. First exopodal segment produced into spinous

process at outer distal corner; 1 accessory hyaline lobe present near base of spinous process;

inner distal corner produced into small triangular hyaline lobe. Second exopodal segment 1.7

times longer than wide (Pl. 8b), carrying small hyaline button near mid-inner margin; lateral

spine inserted on distal third, moderately strong, as long as segment, incurved, acutely pointed

with spinules on distal outer and inner margins. End claw 0.6 times as long as right P5, distal

third bent inwardly and bearing spinules on inner margin. Endopod longer than first exopodal

segment, incurved, with a row of apical spinules.

Left P5 reaching mid-margin of second exopodal segment of right P5. Coxa roughly

rectangular, with hyaline spine arising from a lobe-like strucrture. Basis rectangular, 1.7 times as

long as wide, with 1 large, lamellate hyaline lobe on inner distal margin and with 1 sensory seta

at outer distal corner. Exopod inner margin arc-like at midlength, with a series of serulations,

remarkably uniform in size and with usual 2 hairy pads; apex of exopod with usual combination

of digitiform appendix and spinulate seta. Endopod unisegmented and dilated proximally, with 1

row of long apical spinules.

Variation

Total body length of male (exclusive of caudal setae) varies from 1.79 mm-1.90 mm. On

male right P5, the shape and size of hyaline lobes on basis and second exopodal segment are

subject to some variation, as in Fig 13b, d.

Remarks

Morphologically T. defayeae n. sp. is somewhat more closely related to the Southeast

Asian T. ruttneri (Brehm, 1925) than to any of its eleven valid Indian congeners. The affinities

30

between these two species are apparent from the following characters: male left P5 exopod,

hyaline lobes on the basis and second exopodal segment of male right P5, habitus in both sexes,

and the nature of spines on the grasping antennules. However, a critical comparison reveals

several subtle but valid differences between these taxa. For example, as for the male, the frontal

hyaline lobe of right P5 is large, thumb-like vs. small, digitiform; the hyaline process at the inner

distal corner of first exopodal segment small vs. large; second exopodal segment without vs. with

hyaline lobe between lateral spine (aculeus) and end claw, and with vs. without tiny hyaline lobe

near inner margin on caudal face; left P5 basis with vs. without hyaline lobe; the spinous process

on 13th

segment short vs. long. As to the female, the caudal rami without vs. with hairs on outer

margins; the armature elements on endopod stout and spiniform vs. slender and setiform; and the

coxal spines of P5 large vs. small.

The morphological relationships of T. defayeae n. sp. with the Indian species are listed in

Table 5. Based on the proximal hyaline structure on basis and second exopodal segment of the

male right P5, Defayeae (2002) grouped T. ruttneri with the Asian T. doriai, T. vandouwei, T.

hebereri, T. oryzanus and T. foresti Defaye 2002. However T. defayeae n. sp. is distinctly

different not only from these species but also its other congeners by a unique combination of the

following characters: in the male the right P5, basis has a large, thumb-like frontal hyaline lobe;

first exopodal segment is produced into only a short hyaline lobe at inner distal corner; the left

P5 basis has distinct hyaline lobe on inner margin; the saw has uniformly minute serrations with

short radii. In the female, the genital double-somite is produced into a small chitinous lobe at

right distal corner; no hair on outer margins of caudal rami; and the P5 ednopod has sturdy, short

spiniform setae.

31

Etymology

The new species is named in honour Dr. Danielle Defaye, Senior Curator, Muséum

national d‘Histoire naturelle, Paris for her significant contributions to the study of freshwater

copepods.

Ecology and Distribution

T. defayeae n. sp. occurs in shallow, temporary waters (pH 7.0, temperature 29◦C in

Nepal. So far, it has not been known outside its type locality; it co-occurs with N. schmackeri.

Conservation Status: Vulnerable (VU D2).

Tropodiaptomus raoi n. sp.

(Figs 15-17, Pl. 9)

Type locality and material examined

A temporary shallow water pond in the forest near Siddavatam village (14°28′00″N

78°58′00″E), Kadapa district, Andhra Pradesh. The pond is rain-fed, seasonal, depth 5 m, air

temperature 32°C, water temperature 29 °C; pH 6.0, January 13, 2005, leg. D. Ambedkar.

Holotype adult male dissected on 4 slides, allotype female dissected on 4 slides each; 1

male and 1 female paratypes undissected, preserved in alcohol. The type material is kept in the

Department of Zoology, Acharya Nagarjuna University, pending transfer to the Muséum national

d‘Histoire naturelle, Paris. .

Diagnosis

Male: on right antennule, spine of 13th segment moderately strong and spinous process

on antepenultimate segment hook-like and longer than next segment. Right P5: inner margin of

basis with triangular hyaline lobe subproximally, in addition to a short hyaline growth close by.

First exopodal segment produced into a triangular spinous projection at outer distal corner.

32

Second exopodal segment with small, triangular knob (supplementary process) inserted on

dorsomedial surface near base of lateral spine; a small hyaline lobe present subproximally near

inner margin. Lateral spine short, as long as segment and inserted at distal third of the outer

margin of the segment End claw twice as long as the second segment. Endopod as long as first

exopodal segment. Left P5: basis rectangular, with a small hyaline lobe near outer distal corner

on anterior plane. Exopod roughly spatulate, twice as long as wide, inner distal margin nearly

straight with a series of fine serulations. Endopod pyriform, vaguely 2-segmented.

Female: Postero lateral wings asymmetrical, left being larger than right wing. Genital

somite with small bulge at about mid-outer margin and outer distal corner slightly produced into

rounded lobe, right genital spine directed laterally and left genital spine posterolaterally. P5:

Basis with short slender seta. First exopodal segment slender and subcylindrical. Endopod

shorter than first exopodal segment; setae moderately strong and naked.

Description of adult male (holotype) (Figs 15, 16, Pl. 9a-c)

Total length exclusive of caudal setae 1.77 -1.99 mm (n = 2). Suture separating pedigers

4 and 5 complete. Pediger 5 produced into small, almost symmetrical, triangular postero-laterally

directed wings; each wing with apical relatively large spine and subproximal, inner small spines.

Urosome of 5 somites, attenuating but little behind and nearly straight. Genital somite

with left side indentation and right caudal corner armed with fine sensillum. Fourth urosomite

asymmetrical, right distal corner being produced and rounded. Caudal rami symmetrical; each

ramus twice as long as wide, with hairy inner margins.

Left antennule as in female. Right antennule with spine on each of segments 8 and 10-13,

and 15; spine on segment 13 moderately strong. Relative length of spines in decreasing order as

33

follows: 13>15>11>10>12>8. Spinous process on antepenultimate segment lined with thin

hyaline lamella, longer than next segment, apical part hook-like (Fig. 15c, d, Pl. 9a).

Right P5 (Fig. 16a-b, Pl.9b,c). Coxa as long as wide, hyaline spine arsing from a lobe at

about the middle of the segment. Basis roughly rectangular 1.5 times longer than wide; inner

margin with triangular hyaline lobe subproximally, in addition to a short hyaline growth

occurring close by; usual sensory seta near outer distal margin. First exopodal segment produced

into a triangular spinous projection at outer distal corner. Second exopodal segment roughly

rectangular, twice as long as wide with triangular knob (supplementary process) inserted on

dorsomedial surface near base of lateral spine; a small hyaline lobe present subproximally near

inner margin. Lateral spine inserted at about distal third of the outer margin of the segment,

slightly shorter than the segment and with short spinules on distal outer and inner margins. End

claw twice as long as the second segment, doubly curvd, sickle-shaped and with a row of

serulations on inner margin barring proximal region. Endopod as long as first exopodal segment,

tapering towards apex, with two rows of apical spinules.

Left P5 overreaching first exopodal segment of right P5. Coxa subrectangular, armed

with small hyaline spine arising from a medial lobe-like structure on caudal surface. Basis

somewhat rectangular, 1.3 times longer than wide, with a small hyaline lobe near outer distal

corner on frontal plane (Fig. 16a) and with usual slender seta. Exopod roughly spatulate, twice

as long as wide, inner distal margin nearly straight, with a series of fine serulations, 2 usual

hairy pads in center, proximal one larger and set just adjacent to endopod; apex of exopod with

the usual finger-and-thumb-combination (Fig. 16a, b, Pl. 9c.); the ‗finger‘ rather slim, and

beset with spinules, about as long as the ‗thumb‘. Endopod pyriform, vaguely 2 segmented

with apical and subapical row of spinules.

34

Description of adult female (allotype) (Fig. 17, Pl. 9d, e)

Total length (exclusive of caudal setae) 1.40-1.7 mm (n = 2). Rostral spines as in Fig.

17c. Fourth and fifth pedigers completely fused; fifth pedigerous wings asymmetrical, left wing

being larger than right wing, each wing bilobed with outer large apical spine and inner spine.

Urosome of 2 somites; genital double-somite 1.6 times as long as wide and 1.2 times

longer than anal somite and caudal rami combined, slightly asymmetrical, with small bulge at

about mid-outer margin and outer distal corner slightly produced into rounded lobe; spines

lying opposite to each other subproximally; right spine directed laterally, tiny left spine directed

postero laterally; anal somite telescoped into genital double-somite and deeply cleft; caudal rami

symmetrical with hairy inner margins. In lateral view genital boss conspicuous with genital

opening posterolaterally (Fig. 17b, arrow).

Armature of cephalic appendages as well as natatory legs as in T. defayeae n. sp.

Fifth legs (Fig. 17d, Pl. 9d, e): symmetrical, coxal spine arising from conical posteriorly

directed lobe. Basis 1.5 times longer than wide, with a slender seta at outer distal margin. First

exopodal segment slender, subcylindrical and 2.6 times longer than wide. Second exopodal

segment tapering to a strong inwardly curved claw, distal inner and outer margins fringed with

spinules; lateral spine small; third exopodal segment rectangular, distinct, about twice as wide,

bearing 2 unequal naked setae; outer seta fused to the segment and spiniform; inner seta 4 times

longer than outer seta. Endopod unsegmented, 0.6 times as long as first exopodal segment and

armed with 2 long, moderately strong, spiniform setae; outer apical seta 1.2 times longer than

subapical inner seta, a pecten of spinules occurring at the base either of seta (Pl. 9e).

Ovigerous females not seen in the present collections.

35

Etymology

The species is named in honor of Dr. T. R. Rao, Professor of Zoology (retired), Delhi

University, Delhi, for his significant contribution to zooplankton ecology.

Remarks

Among the Indian species, T. raoi n. sp. is somewhat close to T. defayeae n. sp. in the

following features. In the female, the nature of postero-lateral wings and the genital double-

somite with a proturberance at right distal corner; in male P5, the overall shape of the second

exopodal segment and its hyaline structures, and the general details of left P5 exopod. However,

the two species are distinctly different from each other in various other respects: the nature of

armature elements on the female P5 endopod, the relative size of spinous structures on the

grasping antennule, the shape of basis and its hyaline lobes on male right P5, the shape of left P5

basis with or without inner hyaline lobe, etc. The detailed morphological relationships of T. raoi

n. sp. with its other Indian congeners are as given in Table 4.

Ecology & Distribution

Tropodiaptomus raoi n. sp. is the only representative of Tropodiaptomus from Kadapa

district. Judging by the nature of its type locality, T. raoi n. sp. seems to prefer turbid shallow

waters. It is not know outside its type locality.


Tropodiaptomus keralaensis n. sp.

(Figs 18-21, Pls. 10, 11)

Type locality and Material examined

A turbid, turbid pond at Anzumurthymangalam village near Trichur (10° 31′ 12″ N,

76° 12′ 36″ E), Kerala; depth c. 1 m, air temperature 32°C, water temperature 29°C, pH 6.0;

36

marginal vegetation consisting mainly of Marselia, December 29, 2005. Leg. Y. Ranga Reddy

& D. Ambedkar.

Holotype adult male and allotype adult female dissected on 5 and 4 slides respectively.

Paratypes: 1 male and 1 female in alcohol. Type material is kept in the Department of Zoology,

Acharya Nagarjuna University, pending transfer to the Muséum national d‘Histoire naturelle,

Paris.

Diagnosis

Male: right posterolateral wing larger than left one. Urosomite 4 produced backwards

into distinct triangular process at right distal corner. On right antennule, spine on segment 13

transformed into a hook-like structure apically, spinous process on antepenultimate segment

longer than next segment, straight, apical region hook-like. Right P5: coxa with long hyaline

spine on large lobe arching over basis. Basis subquadrate and with a chitinous, wavy ridge

starting near coxal spine lobe and running obliquely to inner margin, one thumb-like hyaline

lobe obliquely oriented at subproximal region on anterior plane, close to inner margin; another

but small lobe inserted close by on inner margin. First exopodal segment produced at outer distal

corner into a distinct spinous projection; inner distal corner with large, conical hyaline lobe.

Second exopodal segment characteristic in shape, with distal part beyond insertion of lateral

spine being narrow; a chitionus knob inserted on dorsomedial surface and obliquely directed; a

tiny elliptical hyaline structure occurring between lateral spine and end claw. A tiny hyaline

button present on subproximal inner margin; lateral spine longer than the segment, and arising

from distal third of segment. Endopod longer than first exopodal segment; apex rounded with

apical row of long spinules. Left P5: basis inner margin with long, narrow, hyaline lamella.

Exopod characteristic in shape, distal half being narrow; inner distal region arc-like, finely

37

spinulose with short radii; another spinular row running from top to subproximal region and

almost parallel to inner margin.

Female: caudal rami with hairy outer and inner margins. P5: basis with relatively long

sensory seta, extending up to proximal third of first exopodal segment. Inner seta on third

exopodal segment extending beyond mid length of end claw. Endopod about half as long as first

exopodal segment, bearing two moderately unequal naked spiniform setae.

Description of adult male (holotype) (Figs 18, 19, Pls. 10b-e, 11a-d)

Body size 1.30-1.57 mm (n = 5) exclusive caudal setae. Rostral spines as in Fig. 18b.

Fourth and fifth pedigers separated by a complete suture. Wings of fifth pediger asymmetrical,

right wing slenderer and longer than left wing; each wing with relatively large apical spine and

minute subprximal inner spine. Urosome of 5 somites, attenuating behind and gradually bending

to right side. Genital somite with tiny sensory spine on dorsal surface of inner distal corner.

Urosomite 4 asymmetrical, right distal corner produced backwards distinct triangular projection.

Caudal rami 1.8 times as long as maximum width, with hairy inner margins.

Left antennule as in female. Right antennule with spine on each of segments 8 and 10-13

and 15; spine on segment 13 transformed into a hook-like structure apically (Fig. 18c,

Pl..10b,11a). Relative length of spines in decreasing order as follows: 13>15>11>10>8>12.

Spinous process on antepenultimate segment longer than next segment, straight apical region

hook-like, slender and lined with narrow hyaline membrane (Fig. 18d, Pl. 10c).

Armature of appendages as well as natatory legs as in T. defayeae n. sp.

P5 asymmetrical, extremity of left leg5 reaches beyond first exopodal segment of right

P5. Right P5. (Fig. 19 Pls. 10d-e, 11b-d). Coxa as long as maximum width, with long hyaline

spine on large lobe projecting over basis. Basis subquadrate, 1.2 times longer than wide, 1

38

thumb-like hyaline lobe onliquely oriented at subproximal region on frontal plane, close to inner

margin; another but small lobe inserted close by on inner margin; sensory seta near outer distal

corner. Basis with thin, chitinous, wavy ridge starting near the lobe of coxal spine and running

obliquely to inner margin. First exopodal segment partly telescoped into basis, outer distal corner

produced into a distinct spinous projection; inner distal corner with large, conical, hyaline lobe

distinctly produced into a spinous projection. (Pl. 10e, arrow). Second exopodal segment about

twice as long as maximum width, with convex outer margin and concave inner margin; distal

part beyond insertion of lateral spine narrow; a chitionus knob inserted on dorsomedial surface

and obliquely directed; a tiny elliptical hyaline structure occurring between lateral spine and

end claw. A tiny hyaline button present on subproximal inner margin; lateral spine slightly

longer than its segment and arising from distal third of segment and with a row of spinules on

inner distal margin; end claw 0.7 times as long as the same leg, doubly curved; inner margin

except for proximal part beset with fine spinules. Endopod longer than first exopodal segment;

apex rounded with apical row of long spinules.

Left P5: extending beyond first exopodal segment of right P5; coxa subquadrate, 1.4

times longer than wide, with a delicate spine inserted near distal corner; basis elongately oval 1.6

times longer than wide, with a usual slender sensory seta; inner margin with long, narrow,

hyaline lamella on inner distal margin. Exopod characteristic in shape, distal half being narrow;

inner distal region arc-like, finely spinulose with short radii; another spinular row running from

top to subproximal refion and almost parallel to inner margin; usual hairy pads, proximal one set

just under endopod; apex of exopod with finger-and-thumb combination, the ‗finger‘ rather slim

and beset with radial spinules, about as long as ‗thumb‘, which is cylindrical and apically

rounded. Endopod vaguely 2- segmented, with apical row of spinules.

39

Description of adult female (allotype) (Figs 20, 21, Pl. 10a)

Total body length exclusive of caudal setae 1.76- 2.0 mm (n=5). Rostral spines (Fig.

20c) well-developed and acute. Pedigers 4 and 5 completely fused without lateral indentation;

posterolateral wings well developed, bilobed with 2 spines; apical one, as usual larger than inner

one.

Urosome of 2 somites; genital double-somite somewhat asymmetrical, left proximal

being dilated; 1.6 times as long as anal somite and caudal rami combined; 2 conspicuous,

unequal, dorsolateral spines, lying opposite to each other subproximally; right spine lying on

dorsal surface and posteriorly oriented; left spine laterally dirtected; caudal rami parallel,

symmetrical, 1.5 times as long as wide, with hairy outer and inner margins.

P5 (Fig. 21 Pl. 10a): coxa symmetrical, with stumpy subacute spine on a lobe at outer

distal corner. Basis with relatively long sensory seta, extending up to proximal third of first

exopodal segment; first exopodal segment roughly cylindrical and 2.4 times longer than wide

with convex outer and concave inner margin; end claw with spinulate outer and inner margins;

lateral spine represented by a short spine: third exopodal segment represented by a prominence,

bearing 2 unequal, naked spines; inner seta slender and 2.6 times longer than outer spine and

extending beyond midlength of end claw. Endopod unsegmented about half as long as first

exopodal segment, bearing two moderately unequal naked spines, inner subapical seta 0.6 times

longer than endopod, each seta with a pecten of spinules at base.

Etymology

The specific epithet alludes to the the state of Kerala in southwest India where the new

species was collected. The name with the Latin suffix ―-ensis‖ is an adjective for place.

40

Variation

Total body length of male (exclusive of caudal seta) 1.3-1.6 mm, female 1.5-1.8 mm. On

male right P5, the proximal hyaline lobe on basis, the accessory hyaline lobe on the second

exopodal segment, and endopod are subject to variation.

Remarks

T. keralaensis n. sp. closely resembles the Philippine T. lanoanus Kiefer, 1982. The

spectacular morphological morphological affinity between these two species is at once evident

from the form of the second exopodal segment and the position and size of the lateral spine

borne by it. The close kinship of these two species can also be noticed in the following

characters: in the female, the posterolateral wings and the armature elements of the endopod of

P5 (the other details of female are not given for T. lanoanus by Kiefer, 1982); in the male, the

spinous process of the right antennule including that of the antepenultimate segment and the

asymmetric fourth urosomite. A critical comparison, however, shows a series of differences

between the two species: in the male P5 of T. keralaensis n. sp., the exopod of left leg slender vs.

stout, distal inner margin as a single lobe vs. bilobed, right P5 basis with thumb-like vs.

digitiform proximal hyaline outgrowth, without vs. with hyaline lobe near inner distal corner;

first exopodal segment with large vs. small hyaline outgrowths; second exopodal segment with

concave vs. nearly straight inner margin, convex vs. straight outer margin, and accessory hyaline

structure large vs. small, conical vs. lobe-like, and inserted at about the middle vs. near inner

distal corner; 13th

segment of right antennule without vs. with accessory spine; in the female, the

outer margins of caudal rami naked vs. hairy. How the T. keralaensis n. sp. is related to its Indian

congeners can be understood from the tabulated data (Table 5). It is thus remarkable that the

41

close set sister species of T. keralaensis n. sp. is not any of its Indian congeners, but the

Southeast Asian T. lanoanus of the Phillippines.

Ecology and Distribution. T. keralaensis n. sp. was collected in a shallow temporary turbid

pond with marginal vegetation ( temperature is 29ºC, pH 7.5 and Secchi transparency 48 cm). It

is so far known only from its type locality.

Conservation Status: Vulnerable (VU D2)

Tropodiaptomus venkataramani n. sp.

(Figs. 22-25, Pls. 12, 13)

Type locality and Material examined. A small man-made temple pond in the

Tirupurankundram Kasi Viswanath temple in Madurai town (9° 52′ 12″ N, 78° 4′ 12″ E),

Madurai district, Tamilnadu State, 16 June 1971,leg. K. Venkataraman.

Holotype adult female and allotype adult male dissected on 6 and 4 slides, respectively,

paratype adult male mounted whole on a single slide. Type material is kept in the Department of

Zoology, Acharya Nagarjuna University, pending transfer to the Muséum national d‘Histoire

naturelle, Paris.

Diagnosis

Male: right wing shorter than left one. Urosome 4 asymmetrical, produced into a short

triangular process at outer distal corner. On right antennule, spine on segment 13 short and stout

with one accessory hyaline lobe; spinous process on antepenultimate segment slightly longer

than next segment and hook-like apically. Right P5: coxal lobe large, with articulate seta; basis

with 4 hyaline lobes including a large conical lobe on frontal face, second exopodal segment oval

in out line; lateral spine inserted at the same level as end claw. Endopod as long as first exopodal

42

segment. Left P5: basis with small distal hyaline lobe. Exopod oval in outline, with fine, similar

serrulations on inner margin.

Female: right posterolateral wing smaller than left one. Caudal rami with hairy inner

margins. P5: coxa with large spine arising from a lobe like structure. Basis with 1 small hyaline

outgrowth on caudal surface near distal margin. Endopod as long as first exopodal segment;

apical seta as long as endopod with stiff setules on distal outer margin.

Description of adult male (holotype) (Figs 22, Pl. 12b-e, 13a)

Body size exclusive caudal setae 1.90 mm. Rostral spines as in Fig. 22c. Body widest at

caudal border of first pediger. Lateral wings of fifth pediger strongly asymmetrical, left wing

being longer than right wing. Each wing with a pair of small hyaline spines.

Urosome of 5 somites, Genital somite with short spine at right distal corner. Fourth

urosomite asymmetrical, with outer distal corner being prominently produced into conical

spinous process, overreaching midlength of anal somite. Caudal rami symmetrical, 1.6 times as

long as wide with hairy inner margins; dorsal jointed seta of left ramus slightly longer than that

of right ramus; all setae slightly dilated proximally.

Left antennule as in female. Right antennule (Fig. 22d-h, Pl. 12c-e) with spine on each of

segments and 8 and 10-13 and 15; segment 13 with characteristically short and strong, and

with 1 accessory triangular lobe (Fig. 22d arrow, Pl. 12d arrow). Relative length of spines in

decreasing order as follows: 13>15>11>10>8>12. Antepenultimate (Fig. 22e-h) produced

somewhat hook-like spinous process, slightly longer than next segment, and lined with narrow

hyaline lamella.

P5 (Figs 23, Pls 12f, 13a). Right P5: coxa 0.7 times longer than wide and produced into

subtriangular lobe at distal inner angle. Basis roughly rectangular, 1.4 times longer than wide,

43

with 3 hyaline lobes on innermargin; proximal lobe squarish, relatively larger than other 2 lobes,

as illustrated; on frontal surface, 1 hyaline lobe modified into strong spinous projection reaching

inner margin; sensory seta short, arising from outer distalcorner; first exopodal segment about

twice as wide as long, outer distal corner produced into short spinous process; inner distal corner

with small hyaline process; a large broadly triangular hyaline lobe occurring on caudal plane at

about the middle of posterior border. Second exopodal segment subquadrate, 1.4 times as long as

wide, with convex outer and concave inner margins; 1 small hyaline lobe occurring on inner

margin; a large conical accessory structure inserted dorso-distally and oriented towards base of

lateral spine ; lateral spine strong, 1.2 times longer than its segment at about the same level as

end claw, inserted at outer distal corner and ornamented with a row of spinules on inner margin;

2 hyaline lobes present between lateral spine and end claw; end claw sickle-shaped, 2.8 times

longer than the exopod 2, lined with tiny spinules along inner margin barring some distance

proximally. Endopod subquadrate, as long as inner margin of first exopodal segment, apex

rounded with a row of fine spinules. Left P5: reaching beyond inner margin of right P5 basis.

Coxa somewhat quadrate, armed with slender spine arising from a lobe-like structure near distal

outer corner. Basis elongate, somewhat quadrate, 1.6 times longer than wide, a tiny hyaline lobe

on frontal surface close to subproximal inner margin, and another relatively large, somewhat

rectangular lobe on inner margin; usual slender seta near outer distal margin. Exopod distinctly

dilated at about the middle of arc-like inner margin; inner margin right from apex finely and

uniformly serrulated with short radii and hairy pads in center; apex of exopod with usual finger-

and-thumb combination. Endopod apparently unsegmented with apical row of somewhat large

spinules.

44

Description of adult female (allotype) (Figs 24, 25, Pls 12a, 13b,c)

Total length exclusive of caudal setae 1.89 mm. Rostral spines strongly developed and

acute (Fig. 24b). Fourth and fifth pediger fused together. Lateral wings of fifth pediger bilobed,

right wing larger than left one; each wing with a pair of hyaline spines.

Urosome of 2 somites: genital double-somite symmetrical, 1.8 times longer than wide

and 2.6 times longer than anal somite and caudal rami combined and with two equal dorsolateral

spines lying opposite to each other at proximal third; anal somite partially telescoped into genital

double-somite, slightly longer than caudal rami and deeply cleft; caudal rami parallel,

symmetrical, with hairy inner margins.

Morphology of all cephalic appendages as well as natatory legs from P1- P4 as in T.

defayeae n. sp.

P5 (Fig. 25d, Pl. 13b,c). Coxal spine large, conical, pointed arinsing from a lobe-like

structure. Basis with usual slender seta; in addition, a tiny triangular hyaline outgrowth occurring

medially close to caudal margin on frontal plane. First exopodal segment 2.1 times longer than

wide. Lateral spine of second exopodal segment represented by a short spinule. Third exopodal

segment squarish armed with two unequal seta; inner seta long, extending ¾ of end claw; outer

seta modified into short acute outer spine, which is fused to the segment. End claw with

spinulose outer and inner margins. Endopod long, equaling inner margin of first exopodal

segment; armed with 2 long, strong unequal setae; outer apical seta about as long as endopod,

and stiff setules on distal outer margin, inner subapical seta 0.7 times as long as outer spine; each

seta with a pecten of spinules at base; spinules of proximal pecten smaller than those of apical

pecten and lying on frontal plane.

45

Etymology

The new species is named for Dr. K. Venkat Raman, presently Director, Zoological

Survey of India, Kolkata, who collected the sample containing the new species.

Variation

Total body length of male (exclusive of caudal setae) 1.4-1.6 mm, female 1.5-1.8 mm.

The size and shape of the coxal spines on female P5 (Fig. 25e-f), as also the Schmeil‘s organ on

middle endopodal segment of P2 (Fig. 25a-c), the spinous process of the male right antennule

(Fig. 22e-h), and the hyaline structures on the basis, first and second exopodal segments, and the

spinous process of the first and second exopodal segments (Fig. 23b-e) show some

interpopulation variation.

Remarks

T. venkataramani n. sp. is unique in the genus Tropodiaptomus as a whole by possessing

an oval-shaped second exopodal segment on the male right P5 such that the lateral spine and the

end claw lie almost at the same level and separated by a nearly straight line. Further the setae on

the female P5 endopod are unusually long, a character shared with the Indian T. euchaetus and

also the Vietnamese T. foresti. In the latter, the setae are modified into simple, sturdy spiniform

structures. T. venkataramani n. sp. is entirely different from both these species in various other

details.

As for other Indian species, T. vicinus is somewhat close to T. venkataramani n. sp. in

regard to the shape of the second exopodal segment of the male right P5 and the alignment of

the lateral spine and end claw. However, the former is principally different from the latter by

having bilobed vs. unilobed saw, shorter vs. long setae on the female P5 endopod, slender vs.

stout male left P5 exopod, short vs. long, digitiform vs. claw-like spinous process on the

46

antepenultimate segment and so on. The morphological differences of T. venkataramani n. sp.

with other congeners are as listed in Table 5.

Ecology and Distribution. Ecology of this species is not known except that it was found in a

temple pond. It was not found in any other sample collected from Tamilnadu State.


Tropodiaptomus hebereri (Kiefer, 1930)

(Fig. 26)

Type locality: A pool in the marshy locality of Java, Indonesia.

Female

body size 1.5-1. 6. Rostral spines 40 µm in length. Last thoracic segment dorsally with

rounded hump that can be clearly seen in lateral view. Fifth pedigerous wings somewhat

asymmetrical, the left one longer than right. Genital double-somite slightly dilated proximally,

with a very small sensillum on either side, outer distal region enlarged and produced. Outer

margin of caudal rami without hair. Antennules extending up to the middle of the genital double-

somite. Middle endopod segment of leg 2 with Schmeils organ. P5 as illustrated. Endopod with

two terminal setae as in other Tropodiaptomus species.

Male

body size 1.35-1.4 mm. Fifth pedigerous wings symmetrical. Right antennule with small

spine on segment 10, 11. Spine on segment 13 long, slender and with 1 dorsal accessory spine.

Spine on segment 15 also somewhat long. Spinous process on antepenultimate segment

somewhat straight and with hook-like pointed tip. P5: coxa with long hyaline spine. Basis longer

than wide; inner margin lined carrying 2 hyaline outgrowths; also1 strong spiniform outgrowth

47

occurring on anterior surface close to proximal inner margin. First exopod with relatively long

spines at outer distal corner and a hyaline plug on distal inner corner. Second exopod

remarkably broad, with strong, slightly curved lateral spine with hyaline accessory spine near its

base. Terminal claw characteristically curved. Left P5: basis relatively short. Inner margin of

exopod (saw) with uniformly rounded serulations.


The ecology of this species not known though it was reportedly found in several

unspecified localities in India by Brehm (1953). Clearly, this is more common in South East

Asian region of Java, Sumatra and China (Yunnan) (see Dussart & Defaye, 2002) than in India.

Conservation Status: Lower Risk (LR nt)

Tropodiaptomus mutatus (Kiefer, 1930)

(Fig. 27)

Type locality: Khulna, Bangladesh, bordering the Indian State of West Bengal.

Female

Length 1. 5 mm. Right wing somewhat smaller than left wing. Genital double-somite

somewhat dilated proximally on right side and inner distal corner without any protuberance.

Caudal rami without hairs on outer margins. Antennules reaching up to the caudal end of genital

double-somite. P5 as in Fig. 27c.

48

Male

Somewhat smaller than female. Right antennule with remarkably slender spine on

segment 11 and it is twice as long as the spine on segment 10; spine on segment 13 strong and

without any accessory spine on dorsal surface. Spinous process on antepenultimate segment

claw-like and shorter than following segment. P5 as in Fig.27f; the details of the segment

proportions as illustrated; basis of right leg without spiniform-like hyaline lobe on frontal surface

near inner margin. Second exopod slender with relatively short and weakly curved terminal claw.

Endopod shorter. Left P5 with simple saw with finely denticulated inner margin and with short

endopod.

Remarks

T. mutatus has hitherto been reported only by Brehm (1953). Animals that he found in

different samples were said to be mainly having radial stripes on the saw of left exopod of male

P5, based on which Brehm concluded they are ‗mutatus‘. However, Kiefer‘s figures do not show

these stripes as distinctive of ‗mutatus‘. Unfortunately, Brehm did not depict the specimens that

he determined as ‗T. mutatus‘.

Distribution. Though this species has reportedly been found in India (Dussart & Defaye, 2002),

the exact localities of its occurrence are not known .


49

Tropodiaptomus vicinus (Kiefer, 1930)

(Fig. 28)

Type locality: Luckarac Lake, Sunda Islands.

Female: 1.3-1.5 mm. Rostral spines about 35-40 µm long. Metasomal wings nearly

symmetrical, outer corner (with one small hyaline spine) obliquely directed, caudal margin

deeply indented, lying close to the proximal bulge genital double-somite left with reaching the

spine of left genital double-somite, right wing somewhat shorter. Genital double-somite only

very slightly dilated proximally, right distal corner not produced. Caudal rami with hair on outer

and inner margin. Antennules reaching somewhat upto caudal rami. Middle endopod segment of

leg 2 with Schmeil‘sorgan. P5: Terminal setae of endopod of almost similar length with circle of

fine hairs.

Male

Length 1.2 -1.3 mm. Rostral spines as illustrated. Fifth pediger and urosome as in figure.

Right antennule spinous process on segments 8, 10, 11 small, spine on 13 segment long and

slender with accessory spine on dorsal surface. Segment 15 with strong spine. Spinous process

on antepenultimate segment straight, tip blunt. P5 drawings showing all important details of

segment proportions and their ornamentation. Especially the saw lobes which are fine and deeply

bilobed and ornamented with very fine denticles.

Ecology . T. vicinus occurs in littoral regions and swampy areas.

50

Distribution

Rice fields and pools of India; Toba Lake of Sumatra; rice fields of Malaysia, and

Mindanao Island. Brehm (1953) repoted T. vicinus from Yanaon (= Yanam) near Kakinad town.

According to Dussart & Defaye (2002), T. vicinus is also distributed in Thailand, Philippines and

East Kalimantan. In Thailand, this species is restricted to ponds and rivers (see Sanoamunag,

1999).


Tropodiaptomus signatus Kiefer, 1982

(Fig. 29)

Type locality: Unspecified locality in India.

Female

Body size. 1.45-1.5 mm. Rostral spines somewhat 40 µm long. Fifth pediger without

dorsal hump. Metasomal wings nearly symmetrical, outer corner of each wing with relatively

large spine. Genital double-somite with a swelling on left proximal region, carrying a small

sensory spine; distal right corner not produced. Outer and inner margins of caudal rami hairy.

Antennules extending up to the caudal margin of genital double-somite; seta longer and sturdier

than in other congeners . P2 with Schmeil‘s organ. Right P5: coxa with large hyaline spine on the

caudal surface. Second exopodal segment sharply bent inward (‗cramped‘) over the first exopod.

Third exopod small with well developed terminal setae. Endopod unisegmented with 2 almost

equal strong setae.

51

Male

Length about 1.35 mm. Fifth pediger and genital somite as in figure; right antennule with

well developed strong spines of different lengths on segments 10, 11, 13 and 15; segment 13

without accessory spine. Antepenultimate segment with claw-like spiniform, which is as long as

the next segment. Right P5: coxa with spherical chitinous plate at inner corner and with

relatively long hyaline spine on the caudal surface. Basis with 3 hyaline lobes on inner margin.

First exopod with 2 spherical hyaline plugs; outer distal corner produced into pointed process.

Second exopod with short thick lateral spine and long moderately curved end claw. Endopod

without any peculiarities. Left P5: the form of the saw and its denticles characteristic.

Remarks

Kiefer found these specimens together with T. orientalis. None of the Asiatic

Tropodiaptomus spp. has such a remarkable hyaline lobe on the left proximal part of genital

double-somite as does T. signatus. This character along the special of grasping antennule and

male P5 prompted Kiefer to describe this as a new species.


Ecology of this species is not known. Even regarding its distribution, it is known only to

be an Indian species (Dussart & Defaye, 2002).


52

Tropodiaptomus euchaetus Kiefer, 1936

(Fig. 30)

Type locality

Nilagiri Mountains of South India, small pool 2 × 1.5 m, about 60 cm depth, somewhat

2316 m from sea level. Habitat near Umbrella tree in Ootacamund, with Utricularia and

filamentous algae. Temperature at noon 22.1°C; pH 6.1.

Female

Length 1.67 mm. Fifth pedigerous wings symmetrical. Outer distalcorner of each wing

produced, obliquely directed, bearing a hyaline spine. Genital double-somite somewhat dilated

proximally bearing on either side strong hyaline spinule. Caudal rami without hairs on outer

margins. P2 with Schmeil‘s organ. Antennules extending almost to the caudal margin of genital

double-somite. Apical armature of the endopod as shown in figure: the apical seta (somewhat 80

μm), sturdy, about twice as long as subapical seta.

Male

According to Brehm (1953), the male is characterised by the following features: spinous

process on the antepenultimate segment of right antennule longer than succeeding segment and

outcurved; spinous process on segment 10 moderately long, that of segment 11 twice the length

of that of segment 10; segment 15 with moderately long spinous process. Caudal rami twice as

long as wide, with hary inner margins. Right P5: intercoxal plate semicircular; coxa with club-

like hyaline outgrowth. Basis as long as wide with rectangular hyaline membrane on proximal

inner margin.Second exopodal segment elongate, somewhat bent, lateral spine almost as long as

53

segment and inserted in the distal half of the segment; accessory chitinous structure in the form

of a very long, characteristic seta. Left P5: exopod large, inner margin bifid; proximal inner

margin smooth; distal margin furnished with fine, short striations

Remarks

Kiefer (1936) originally described T. euchaetus on the basis of females only. The large

setae on the endopod of the female P5 are highly characteristic of this species. In fact, the

specific epithet alludes to this feature. Brehm (1953) described and illustrated the male of this

species from Kodaikanal, but he was not sure whether it was indeed the male of this species. And

he also opined that what he described as male of T. euchaetus could well be a new species, for

which he even suggested the name setiger, attaching importance to the seta-like accessory

sturcute of the second exopodal segment of the male right P5. In this scenario, Seghal (1967)

reported T. ecuhaetus on the basis of three specimens found in a find fish pond in Narsinghpur of

Orissa. The endopod of female P5 have long apical setae. But other characters of the female do

not agree with the Kiefer‘s T. euchaetus. Seghal‘s (1967) descriptions and figures of male of T.

euchaetus are highly erroneous and hence not dependable. Similarly, his key for the Indian

species of the genus Tropodiaptomus is highly misleading. I have no access to the type

material/voucher specimens of this species not I could find it in my present survey. Hence it is

impossible at this stage to provide a reliable account of the male of T. euchaetus. However, for

the time being, Brehm‘s (1953) depiction of the male is treated as belonging to T. euchaetus.

Ecology and Dirtribution The species seems to be confined to ponds of the elevated,

somewhat cooler parts of Nilgiri Hills of South India: Otacamund and Kodaikanal.

Conservation Status: Lower Risk (LR nt).

54

Tropodiaptomus doriai (Richard, 1894)

(Fig. 31)

Type locality: Toba Lake, Sumatra.

Female

Length 1.12-124 mm. Rostral spines relatively short, somewhat 25-35 µm. Fifth pediger

almost symmetrical; fairly flat outgrowth on posterior margin. Genital somite generally

characteristically symmetrical. Proximal part slightly dilated with minute sensillum on each side.

Outer and inner margin of caudal ramus hairy. Antennules relatively short, barely reaching the

posterior margin of genital somite. Middle endopod of leg 2 with small Schmeil‘s organ. P5 both

the terminal setae of endopod provided with hairs.

Male

Length 1.0-1.5 mm. Rostral spines somewhat 30 µm long. Last thoracic segment slightly

asymmetrical. Genital somite without sensillum at anterodistal corner. Fourth urosomite is

produced at right distal corner. Right antennule segments 10 and 11 with very small each. On

segment 13 one long slender spine and one accessory spine near its base on posterior surface.

Spine on segment 15 distinctly short. The spinous process on the antepenultimate segment

straight and shorter than the next segment. P5 as in Fig. 31i. The saw of left exopod bilobed with

fine, somewhat similar denticles. A small chitinous knob present on the caudal surface of second

exopodal segment, sometimes opposite to the inner margin.

55


Ecology of this specis unknown. It is distributed in Sri Lanka, Thailand, Java, Sumatra,

and Sulawesi (Dussart & Defaye, 2002). Though this species reportedly occurs in India (Kiefer,

1982), the exact localities and habitats are not known.


Genus Heliodiaptomus Kiefer, 1932

Heliodiaptomus: Kiefer, 1932a: 473; Shen & Song, 1979: 113; Lai & Fernando,

1981:168; Ranga Reddy & Radhakrishna, 1981: 171; Dussart & Defaye, 1983: 96; 2002: 120.

Generic diagnosis

Kiefer‘s (1932) original definition of the genus Heliodiaptomus has been revised by

Ranga Reddy (1994) as follows: Animals moderate to somewhat large in size (females 1.0-2.0

mm and males 0.7-1.8 mm long). Female: lateral wings of fifth pediger generally moderately

developed; urosome of 3 somites; antennules extending slightly beyond, or sometimes only to

the base of, caudal setae; on P5, endopod without apical setae and end claw with hairy or

spinulose margins, and only exceptionally with denticulate margins. Male: right caudal ramus

without any ornamentation; on right P5, endopod generally cylindrical but varying in size; coxa

with or without lobe at distal inner corner; basis with 1 or 2 small hyaline lobes on inner margin;

lateral spine of second exopodal segment of the same leg usually proximal, sometimes even

articulated to its posterior face; on left P5, second exopodal segment with a short or,

occasionally, elongate, digitiform process and a well-developed seta apically.

Type species: *Heliodiaptomus viduus (Gurney, 1916)


*Heliodiaptomus contortus (Gurney, 1907)

56

*Heliodiaptomus cinctus (Gurney, 1907)

*Heliodiaptomus pulcher (Gurney, 1907)

Heliodiaptomus nipponicus (Kokubo, 1914)

Heliodiaptomus kikuchii Kiefer, 1932

*Heliodiaptomus elegans Kiefer, 1935

Heliodiaptomus kieferi Brehm & Chappuis, 1935

Heliodiaptomus serratus Shen & Tai, 1962

Heliodiaptomus falxus Shen & Tai, 1964

Heliodiaptomus lamellatus Sung, Shen, Sung, Li & Chen, 1975

*Heliodiaptomus kolleruensis Ranga Reddy & Radhakrishna, 1981

Heliodiaptomus puthaiorum Sanoamuang, 2004

N. B. The above-listed, asterisked species are from India.

Keys to the female Indian Heliodiaptomus spp.

1. Posterior border of fourth pedigerous segment with a transverse row of spinules on the dorsal

surface; genital double-somite asymmetrical and longer than other 2 urosomites combined ...….2

Posterior border of fourth pedigerous segment without a transverse row of spinules on the dorsal

surface; genital double-somite symmetrical about as long as other 2 urosomites combined

……………………..…………………………………………………………………….H.elegans

2. End claw of the P5 with denticulate margins ……………………………………….H. viduus

End claw of the P5 with either hairy or finely spinulose margins ……………………………3

3. The spine of the left coxa is larger than that of the right in P5……………….……H. contortus

57

Both spines of coxa are similar in size………………………………………….…….H.cinctus

4. Metasomal wings symmetrical and bilobed……………..……………………...H. kollerurensis

Metasomal wings asymmetrical, the left wing being triangular while the right is relatively large

and somewhat bilobed………………………………………………………………...H. phlcher

Key to the males of Indian Heliodiaptomus spp.

1. The hyaline process of the antepenultimate segment of the grasping antennule

serrated……………………………………………………………………………..H. pulcher

The hyaline process of the antepenultimate segment of the grasping antennule simple……..2

2. End claw of the right P5 swollen and twisted at the base…………………………H. contortus

End claw of the right P5 normal……………………………………………………………….3

3. Right P5 basis with one hyaline lobe inner margin, and exopod 1 with a roughly

trapezoidal or triangular chitionus process on the distal prosterior aspect;… ……….H. viduus

Right P5 basis with two hyaline lobe inner margin: exopod 1 with shortblunt projection on

distal posterior aspect……………………………………………..…………………..H. elegans

4. Lateral spine mesially inserted on second exopodal segmentand; end claw sickle- shaped

…………………………………………………………………………………..H. kolleruensis

Lateral spine subproximally inserted on second exopod segment; end claw middle outcurved

endclaw……………………………………………………………………………….H. cinctus

58

Heliodiaptomus viduus (Gurney, 1916)

(Figs 33-35, Pl. 14)

Diaptomus viduus: Gurney, 1916: 338-339, P1. 2, Figs 11-14 (♂); Sewell, 1934: 75-78, Figs 3a-

d (♀).

Heliodiaptomus viduus: Kiefer, 1932a: 507, F ig. 82; Brehm, 1953: 242-244, Figs 1-2; Brehm,

1963: 159-163, Figs 1-10; Sehgal, 1967: 66-68, Figs 23-26; Rajendran, 1973: 116-117, Figs 3a-

n; Fernando, 1974: 60-61, Figs 238, 249-253;Lai & Fernando, 1981: 168, Figs 45-57; Ranga

Reddy & Radhakrishna, 1981: 162-163, PI.1, Figs 1-4; Dussart & Fernando, 1985: 237-238, Figs

33-38; Ambedkar, 2005: 24-30, Figs 1-13.

Neodiaptomus kamakhiae: Reddaiah, 1964:161-166, Figs 1a-h.

Helidiaptomus latifi: Das, 1974: 47-51, Figs 1-6.

Type locality: Snake‘s pool at Mahintele, Sri Lanka.



Female

Third and fourth pedigers demarcated transverse row of spinules on dorsal surface.

Lateral wings of fifth pediger asymmetrical and armed with 2 unequal spines each wing. Genital

double- somite asymmetrical. Urosome of 3 somites, caudal rami with hairy outer and inner

margins. Leg 5: left coxal spine distinctly larger than right coxal spine, number of denticles

along the lateral margins of end claws slightly variable. Endopod somewhat exceeding midlength

of first exopodal segment.

59

Male

Body ornamentation as in female. Caudal rami 1.4 times as long as wide and with hirsute

inner margins. Right antennule with spines on each of segments 8 and 10-16; spinous process on

antepenultimate segment straight, slightly exceeding half the length of penultimate segment and

fringed with narrow hyaline membrane along outer margin. P5: exopod 1 of right P5 with

trapezoidal chitinous process on posterior surface. Distal outer corner of exopod 1 short and

pointed spinous process. Second exopodal segment elongately ovate; lateral spine inserted

proximally over posterior surface. End claw somewhat dilated at base with generally angular

outer margin. Endopod cylindrical and extending beyond origin of lateral spine on second

exopodal segment. Left P5: basis with two small hyaline lobes; endopod about as long as its

counterpart on right P5.

Remarks

H. viduus shows wide variation within and between populations in the number of

denticles on the end claw of female P5: 0-8 on outer margin and 8-13 on inner margin. The

spinous process at distal outer corner of first exopodal segment on male right P5 varies in shape

from short, blunt to long, pointed; the proximal part of end claw is sometimes narrow with

smoothly curved outer margin or rarely produced into a rounded prominence. The presence of

spinules between third and fourth pedigers in the male is being reported for the first time.

Abnormality: two proximal lateral spines were noticed on second exopodal segment of right P5

in one specimen. The interrelationships of the congeners can be understood from Table 9.

60

Ecology

H. viduus is successful in all kinds of freshwater habitats except in rivers. In the present

study it was found in 86 habitats of 2000 sampling sites. In Andhra Pradesh, H. viduus was found

in shallow, temporary, permanent aquatic habitats when the temperature was 25ºC- 35ºC. It was

noticed in a turbid pond in forest area at Siddavatam near Kadapa town of A. P. In Karnataka and

Tamilnadu H. viduus was found in large village tanks. Its co-occurrence with typical temporary

water forms like the fairy shrimps (Streptochephalus sp.) in river-fed hill-pool speaks of its wide

ecological amplitude. H. viduus co-occurs with P. blanci, N. schmackeri, H. contortous, P.

greeni. and N. lindbergi.

Distribution

Previous records

India, Sri Lanka, Pakistan, Bangladesh, Myanmar, and Thailand. While the species is

not common in its type locality, i.e. Sri Lanka (see Gurney, 1916; Fernando, 1974, 1980), it is

the most common diaptomid in South India (Ranga Reddy, 1994), and its abundance, according

to Hossain (1985), diminishes gradually towards the North. It was not recorded by Kiefer (1939)

in his scientific report on the Yale North India Expedition. According to Das (1974) and Hossain

(1985), it is the most abundant calanoid in Bangladesh. It is so far reported from Salt Lakes,

Calcutta; Indian Museum Tank, Calcutta; Kudra tank, Mirzapur; Portblair; P.W.D. tank,

Ghorwal; Bankipur; Cuttack, Portblaiir; Mysore; Madras; Delhi, and several places in Orissa:

Athmilike, Balasore, Berhampore, Chandwar, Whenkanal, Jenapore, Jaipore, Linghpur,

Narsinghapur, Puri and Sambalpur.Andhra Pradesh: Visakhapatnam, Anakapalli, Guntur,

Kondaveedu, Guntakal, Gooty, Dharmavaram, Tirupathi hills, and Warangal.

61

Present records

H. vuduus is recorded in the present study from Srikakulam, Vijayanagaram,

Visakhapatnam, East Godavari, West Godavari, Krishna, Guntur, Prakasm, Nellore, Hyderabad

and Warangal districts of Andhra Pradesh State and also from Chattisgarh, Tamilnadu and

Kerala States.

Conservation Status: Lower Risk (LR); Least Concern (lc).

Heliodiaptomus contortus (Gurney, 1907)

(Figs36, 37, Pl. 15)

Diaptomus contortus: Gurney, 1907: 28, Figs 9-10; Sewell, 1924: 788, P1. 45, Fig. 5.

Heliodiaptomus contortus: Kiefer, 1932a: 507, Figs 84-86; Brehm, 1950: 11-13, Figs 1a-d;

Brehm, 1953: 247-252, Figs 5-11; Brehm, 1963: 162-163; Ranga Reddy & Radhakrishna, 1981:

163-165, P1.2, Figs 1-10; Ranga Reddy & Devi, 1989: 129-130, Figs 41, 42, 50, 51, 62, 65;

Ambedkar, 2005: 30-33, Figs 1-9.

Type locality: Museum tank, Calcutta, India.


Body size. Female 1.4 -1.6 mm; male 0.8 -1.3 mm.

Female

Fourth and fifth pedigers with a row of dorsal spinules. Lateral wings of fifth pediger

small, rounded, asymmetrical and armed with 2 unequal spines each; right wing with small

rounded prominence, whereas left wing larger than right wing. Genital double-somite relatively

short and asymmetrical, sub-proximal region produced on right side; left genital spine larger than

62

right spine. Caudal rami with hirsute outer margins. P5: left coxal spine distinctly larger than

right coxal spine, second exopodal segment with large, tooth-like lateral spine near the base;

third exopodal segment vestigial, being represented by a minute tubercle, bearing 2 unequal

setae. Endopod shorter than first exopodal segment.

Male

Fourth and fifth pedigers demarcated by a row of thin of spinules. Genital spine

extending slightly beyond midlength succeeding segment. Caudal rami asymmetrical, left caudal

ramus slightly wider than right one, with hairless outer and inner margins. Right P5: basis with

very large hyaline lobe on distal inner middle margin; second exopodal segment characteristic in

shape; lateral spine about as long as the segment; end claw very strong; basal region dilated and

generally twisted. Endopod uniformly narrow slightly bent halfway and much longer than first

exopodal segment, apex rounded with a thin row of spinules. Left P5: Basis without hyaline lobe,

second exopodal segment with well-developed pincers-like terminal processes. Endopod much

shorter than its counter part on right P5.

Remarks

The nature of lateral wings in female, the lateral spine of second exopodal segment agree

with earlier reports and the endopod of male right P5 and the arrangement of spinules between

fourth and fifth pedigers are somewhat variable. The interrelationships of the congeners can be

understood from Table 9. It is worthy of note that the closest sister species of H. contortus is the

Chinese H. falxus (see Shen & Tai, 1964).

63

Ecology

H. contortus has been recorded in roadside canals, ponds, reservoirs, and rice fields. It

was noticed in clear or turbid waters and canal-fed fish ponds and rice fields where the

temperature ranges from 26- 31ºC at pH 6.5-8.0 June - December. Its occurrence in seasonal

rain pools is unlikely. It was found by Ranga Reddy (1994) in a turbid pond (Secchi transparency

ca. 4 cm) on the Nagarjuna University campus from January to March 1984, when temperature

ranged from 24˚c to 30˚c and pH from 7.0-8.9. Pillai (1971) considered it mixohaline (salinity

0.5-30‰). According to Sewell (1934), this species, though usually found in freshwater, would

appear to be somewhat more adaptable to brackish water than Phyllodiaptomus blanci and

Heliodiaptomus cinctus. This species is amenable to cultivation under laboratory conditions.

According to Ranga Reddy & Devi (1989) who raised this species from its eggs, it completes

naupliar phase in 5 days and copepodid phase in 11 days at a room temperature of 24Cº - 28Cº.

It often co-occurs with H. viduus, A. raoi and S. indicus.

Distribution

Previous records

Indian Museum Tank, Calcutta, Chakradharpur, River Hoogly, Goa, Savantadadi, ‗Raie

Temnben‘, Chilka Lake, Chingrighatta, Linghipur, Vengalayapalem, Guntur environs, Lake

Kolleru at Kolletikota.

Present records

All the present distributional records of H.contortus point to its being endemic to India.

Though not common, it appears to be widely distributed in India. In the present study H.

contortus reprted recorded from Vengalayapalem pond near Guntur and Lake Kolleru at

64

Kolletikota in Krishna district, also found in Kaja village, tanks in Prakasam district and few

localities around Acharya Nagarjuna University campus. According to Green (pers. commun.),

this species occurs in Myanmar also. For distribution of localities in India see map.

Conservation Status: LR.

Heliodiaptomus cinctus (Gurney, 1907)

(Figs 38-40, Pl. 16)

Diaptomus cinctus: Gurney, 1907: 29, Figs 11-12; Sewell, 1924: 788, P1. 45, Fig. 4

Heliodiaptomus cinctus: Brehm 1953: 244-247, Figs 3-4; Sehgal, 1967: 57-61, Figs 4-9;

Abraham, 1972: 250-252, Figs 1-7, 11-17, 22-23; Ranga Reddy & RadhaKrishna, 1981: 165-

166, P1. 3, Figs 1-5; Ranga Reddy & Devi, 1990a: 62, Figs 41, 42, 65, 68; Ranga Reddy, 1994:

Figs 37-48.

Heliodiaptomus rangunensis: Kiefer, 1932b: 269-270, Figs 6-10.

Allodiaptomus cinctus: Kiefer, 1936c: 323-325, Figs11-15; Dussart & Fernando, 1985; 236-237,

Figs 28-32.

Allodiaptomus mirabilipes: Kiefer, 1936a: 139-140, Figs 7-8 (♀).

Allodiaptomus raoi: Rajendran, 1973: 126, Figs 7 a-j.

Arctodiaptomus shillongensis: Reddiah, 1965: 25, Figs 1 a-i.

Arctodiaptomus kieferi: Reddiah, 1965: 28, Figs 2a-i.

Eudiaptomus cinctus: Fernando, 1974: 60, Figs 224-247.

Allodiaptomus tiruttanii: Rajendran, 1979a: 5-8, Figs 1a-i.

65

Type locality: Swamp at Chakradharpur, India.



Female

Fourth and fifth pedigers with transverse row of spinules (nearly about 45-50), extending

dorsolaterally. Lateral wings of fifth pediger small, rounded and asymmetrical; left wing

somewhat larger than right wing. Genital double-somite slightly dilated proximally, about as

long as following somites and caudal rami combined, asymmetrical, right side with laterally

directed slender spine and left side with chitinous projection, carrying thick, posteriorly directed

spine. Caudal rami with hair on outer and inner margins. P5: coxal spines are unequal in size,

lateral spine of second exopodal segment tooth-like. Third exopodal segment absent, its place

being occupied by a spine or seta. Other details as illustrated.

Male

Fourth and fifth pedigers with a row of dorsal spinules present (nearly 83-85). Genital

spine small. Second and third urosomites with ventral hairs. Right antennule with spine on each

of segments 8 and 10 -16; spinous process on antepenultimate segment nearly straight, tip

generally hooked. Right P5: coxa produced into large, bifid lobe at distal inner corner. Basis with

roughly crescentic hyaline lobe at midlength of inner margin. Second exopodal segment with 1

proximal lateral spine, about half as long as the segment: in some specimens from localities of

Kolimigundla in Andhra Pradesh and Dindigul near Madurai showing a spinule near distal outer

corner (Fig. 39m arrow). Endopod small, flask-shaped and longer than first exopodal segment.

66

Left P5: basis with 1 narrow hyaline lamella at the middle of inner margin. Endopod smaller than

its counterpart on right P5.

Remarks

Some degree of morphological variation has been observed in the following characters: in

females the number of spinules present between fourth and fifth pedigers, the size of the leftside

protuberance of genital somite and of its spine; in males the shape of distal outer spine on first

exopodal segment of right P5, presence of hyaline button on right P5 basis and as well as the

shape of end claw of right P5. The relationships of this species with its congeners can be

understood from Table 9.

Ecology

H. cinctus is eurytopic species occurring in such diverse habitats as lakes (Sewell, 1924,

1934; Ranga Reddy & RadhaKrishna, 1981), rivers (Ray et al. 1966), rice fields (Ranga Reddy

& Devi, 1990a), crystal clear river pools, irrigation canals, fishponds and slightly elevated,

permanent hill ponds (Ranga Reddy, 1977). Pillai (1971) recorded it in Cochin Backwaters when

salinity was 6.5‰. According to Sewell (1934): ―H.cinctus appears to be a true fresh-water

inhabitant and has but little power of adaptation to brackish water habitat‖. H. cinctus is

amenable to cultivation under laboratory conditions. According to Ranga Reddy & Devi (1990a)

who raised this speicies from its eggs, it completes naupliar phase in 6 days and copepodid phase

in 10 days at a room temperature of 26Cº-31Cº. It is often co-occurs with H.viduus, N. lindbergi

and A. intermedius.

67

Distribution

Previous records

Confined to India, Sri Lanka and Myanmar. In India, It is reported from: Calcutta, Chilka

lake, Chakradharpur, Calicut, Tellicherry, Cochin Backwaters Lake kolleru; Yard pond, Guntur;

and Rangaswami gundem, Akaveedu; a pond at Secunderabad (Ranga Reddy, 1977), It is fairly

widely distributed in India except in the subtropical Kashmir region. Ranga Reddy (1994)

noticed this species at Perintelmanna and Angadippuram (Kerala State), Tiruvegadam near

Madurai (Tamilnadu), Tungabhadra reservoir and a host of other places in Karnataka and Andhra

Pradesh in India.

Present records

In the present study it has been recorded in village tanks of Kerala and Tamilnadu States.

I found on November 23, 2003 only one male specimen in a fishpond at Sangam Jagarlamoodi

village. Dense populations of this species were found in at Bodigari Thota in Nellore,

Kolimigundla village in Kurnool district and Tiruvur in Krishna district of Andhra Pradesh State.

Conservation Status: Least concern (LR).

Heliodiaptomus pulcher (Gurney, 1907)

(Figs 41-43, Pl. 17)

Diaptomus pulcher: Gurney, 1907: 29-30, Figs 13-17.

Heliodiaptomus pulcher: Sehgal, 1967-64, Figs 16-18; Ranga Reddy & Radhakrishna, 1981:

166-168, P1.4, Figs 1-9; Ranga Reddy 1994: Figs 49-62.

Heliodiaptomus pulcher orissaensis: Sehgal, 1967: 67-68, Figs 19-22.

Type locality: Swamp at Chakradharpur, Jharkhand State, India.

68

Material examined

Sample collected from a village tank near Raipur (21° 13′ 48″ N, 81° 37′ 48″ E),

Chattisgarh State. October 24, 2005. Leg. Y. Ranga Reddy .

Body Size. Female 1.5-1.9 mm; male 1.4-1.8 mm.

Female

Dorsal spinules absent between fourth and fifth pedigers. Lateral wings of fifth pediger

small and asymmetrical, left wing produced, narrow and triangular, right wing relatively large

and bilobed. Each wing with 2 unequal spines. Genital double-somite exceeding combined

length of following 2 somites plus caudal rami; subproximal region only slightly dilated and

armed with a hyaline spine on each side. Second urosomite with sensillum on either side

proximally. Caudal rami about as long as anal somite. P5: Coxal spines equal in size. Lateral

spine of second exopodal segment slender. Third exopodal segment distinct, with 2 unequal

spines. Endopod about 2/3 as long as first exopodal segment.

Male

Lateral wings as in Fig. 42a. Genital spine slender and arising from distal outer corner.

Caudal rami 1.8 times as long as wide; on the ventral side of each ramus provided with a

triangular hyaline lobe near disto-medial region; both inner and outer margins hairy. Right

antennule with spine on each of segments 8 and 10-16; spine on segment 11 sharply bent

backwards; antepenultimate segment produced into short, comb-like process with 5-7 teeth. P5:

Coxa produced into large, roughly triangular lobe at distal inner corner. Basis with 1 somewhat

large, hyaline lamella on proximal inner margin. Second exopodal segment bent outwards, with

convex inner contour; 1 small hyaline lobe present at subproximal dilation region; lateral spine

proximal in position and slightly shorter than segment. Endopod barely as long as first exopodal

69

segment. Left P5: Basis with 2 hyaline lobes on inner margin. Endopod longer than its

counterpart on right P5.

Remarks

The number of teeth on the comb-like process of the grasping antennule, the shape of

inter coxal lobe, lateral spine on second exopodal segment on right P5 show intra- and

interpopulation variation. In males, the presence of small triangular hyaline lobe on ventral

surface of each rami is a consistent morphological character which has been overlooked by

earlier workers. For comparision of morphologic characters with other congeners see Table 9.

Ecology

This is the rarest species among the Indian heliodiaptomids. Its distributional records are

indicative of its stenotopic nature. Its presence in the open well at Mallenahalli is apparently due

to its having been washed in by the run-off from the surrounding rice field (Ranga Reddy, 1994).

H.pulcher is somewhat common in the State Chattishgarh when compare with other States of

India.

Distribution

H. pulcher is endemic to India. In the present study it has been recorded in good

numbers in Chattisgarsh State. Previously H. pulcher was known but from a few places, viz.

Chakradharpur (Gurney, 1907); fish ponds at Linghipur and Narsingpur in Orissa State ( Sehgal,

1967); Chilka Lake ( Sewell, 1924); Kondakarla Lake in Andhra Pradesh State ( Ranga Reddy &

Radha Krishna, 1981). Ranga Reddy (October 18, 1988) found this species in an open well in

rice field at a roadside hamlet called Mallenahalli, 16 km from Chickmagalur, in Karnataka

State.

Conservation Status. Vulnerable (VU B1).

70

Heliodiaptomus kolleurensis Ranga Reddy & Radhakrishna, 1981

(Figs 44, 45, Pl. 18)

Heliodiaptomus kolleruensis: Ranga Reddy & Radhakrishna, 1981: 169-171, Pl.5, Figs 1-13.

Type locality: Lake Kolleru, South India.

Material examined: 3 males, 3 females, Lake Kolleru, date?, leg. Y. Ranga Reddy.

Body size. Female. 1.4-1.7 mm; male 1.0-1.4 mm.

Female

Rostrum with 2 sturdy, pointed spines. Pedigers 4 and 5 perfectly fused; dorsal spinules

absent. Posterolateral wings well developed and symmetrical, each wing roughly bilobed, inner

lobe rounded and provided with 1 delicate spine whereas outer lobe narrow, triangular, laterally

directed and tipped with 1 minute spine. Genital double-somite barely as long as succeeding 2

somites and caudal rami combined; proximal part dilated and produced into stumpy arm on each

side; right arm slightly smaller than left arm with minute posteriorly-directed spine; left arm with

a spine directed towards the body axis. P5: coxal spines of both legs equal in size. Lateral spine

of second exopodal segment slender. Third segment distinct, with 2 strong, unequal spines.

Endopod 2/3 as long as first exopodal segment.

Male

Genital spine quite short. Caudal rami symmetrical, 1.5 times as long as wide, without

hairy outer and inner margins. Right antennule with spine on each of segments 8 and 10-15;

spinous process on antepenultimate segment slightly outcurved or, sometimes, straight and

extending somewhat beyond succeeding segment. Right P5: Coxal spine small like its

counterpart on left P5. Basis as long as its distal width, with 1 hyaline lobe at distal inner corner.

Second exopdal segment bent inward, characteristic in shape with proximal 2/3 being dilated;

71

inner margin with small hyaline lobe near subproximal region; lateral spine inserted at about the

middle of outer margin; end claw smoothly curved like and sickle-shaped. Endopod uniformly

narrow, slightly bent inward and longer than first exopodal segment. Left P5: basis about as long

as wide, with 1 hyaline lobe at about midlength of inner margin. Second exopodal segment with

thumb-like process and a modified seta. Endopod much stronger than in right P5.

Remarks

The assignment of this species to the genus Heliodiaptomus should be regarded as

tentative (cf. Ranga Reddy & Radhakrishna, 1981). However, this species shows the following

characters, which accord well with the genus Heliodiaptomus: in female; urosome of 3 somites;

on P5, endopod without apical setae and end claw with spinulate margins. Male: Right caudal

ramus without chitinous tooth on ventral side; on right P5, endopod generally cylindrical; coxa

without a lobe at distal inner margin. However, H. kolleruensis stands out in the genus

Heliodiaptomus by the following characters: well-developed, bilobed metasomal wings, and the

conspicuous arms of the genital segment in the female, and the shape of exopod and mesially

inserted lateral spine on second exopodal segment, and sickle-shaped end claw on the male right

P5.

Ecology

This is a rare species. It is found in large permanent, stagnant, turbid or moderately

transparent, freshwater bodies like ponds, lakes and reservoirs. Its occurrence in seasonal pools

and ponds, and also brackish habitats is hardly likely.

Distribution

H. kolleruensis appears to be endemic to South India, having been reported from Lake

Kolleru, and Bhadrakali tank at Warangal (Ranga Reddy & Radhakrishna, 1981). Subsequently,

72

Ranga Reddy (1994) collected this species in a turbid reservoir on the Nagarjuna University

campus, and in a pond at Jeedimetla.

Conservation Status: CR B1.

Heliodiaptomus elegans Kiefer, 1935

(Fig. 46)

Type locality: Pond near Rangoon, Myanmar.

Material examined: Not found in the present study.

Body size: Female 1.17-1.40 mm; male 1.08-1.14 mm.

Female

Fourth and fifth pedigers fused, but deeply indented laterally. Lateral wings of fifth

pediger well developed and asymmetrical. Urosome of 3 somites. Genital double-somite

symmetrical, about as long as succeeding 2 somites plus caudal rami. Caudal rami parallel with

hairy outer and inner margins. P5: right and left P5 more or less symmetrical. Coxal spine on

either P5 moderately large. First exopod with convex outer margin and almost straight inner

margin. Terminal claw nearly straight, inner margin lined with fine spinules. Endopod

unisegmented.

Male

Fourth and fifth pedigers fused except at lateral margins. Lateral wings of fifth pediger

small and rounded. Urosome of five somites. Second and third urosomites without ventral hairs.

Right antennules with spine on each of segments 8 and 10-16, spinous process on

antepenultimate segment generally longer than next segment and with outcurved apical region.

Right P5 of moderately build. Coxa more or less squarish and produced at distal inner corner into

small crescentic lobe. Coxal spine moderately strong and arising from large hyaline lobe. Basis

73

rectangular, with 2 small hyaline lobes on inner margin. First exopodal segment ending in short,

blunt projection at distal outer corner. Second exopodal segment slender, 2.5 times as long as

median width and with large triangular hyaline lobe proximally below the base of lateral spine,

lateral spine strong, somewhat longer than the segment. Terminal claw strong. Endopod

unisegmented. Left P5: coxa with a small hyaline spine at about mid-length of inner margin;

basis with elongate narrow hyaline lamella; first exopodal segment twice as long as wide,

incurved, with large hairy lobe on inner margin. Second exopodal segment inner margin fringed

with long, coarse hair on proximal half and with fine spinules on distal half. Apical process

short, articulate, conical or somewhat thumb-like. Seta sturdy, almost twice as long as apical

process, feathery and generally outcurved. Endopod flask-shaped, 2-segmented with subapical

row of close-set spinules and spine on each side.

Remarks

Morphologically, H. elegans is close to the Indian H. pulcher, as evident from the habitus

and P5 in both sexes. Other details as in Ranga Reddy & Dumont, 1999.

Distribution

H. elegans appears to be a rare species, restricted to few localities of Southeast Asia and China. It

has been reported from its type locality, a pond near Rangoon, Myanmar (erstwhile Burma) (Kiefer,

1935), from some lotic and lentic habitats of Cambodia (Brehm, 1951a), and from the middle and lower

Yangtse River: Guangdong (Shunde), Guangxi (Guellin), Hubei (Hunggang) and Jiangsu (Wuxi) (Shen &

Tai, 1962). During a 36-year survey of the Indian subcontinent by Ranga Reddy, H. elegans was found

only two occasions i.e., one at Dakha, Bangladesh (Ranga Reddy, 1994) and another in (2010) north-east

part of India. H. elegans inhabits lakes, ponds and streams. According to Shen & Tai (1962), it is ‗more

active in the limnetic than in the sublittorial regions‘.

Conservation Status: CR B1.

74

Genus Allodiaptomus Kiefer, 1936

Allodiaptomus: Kiefer, 1936a: 142; Shen & Song, 1979: 153; Dussart & Defaye, 1983: 98;

2001: 108, 102; 2002: 123; Ranga Reddy, 1987: 132; 1994: 28-30; Dussart & Defaye, 2002:

123.

Generic diagnosis

Ranga Reddy (1987) revised the original definition of the genus Allodiaptomus as

follows: Animals slender and of moderate size, fourth pediger with or without dorsal row of

spinules along posterior boarder. Female urosome of 3 somites. Antennules generally long,

extending beyond caudal setae. On male right P5, coxa produced into lobe-like structure at distal

inner corner; basis with elongate hyaline membrane on inner margin; second exopodal segment

with at least 2 outer lateral spines, a large proximal and a small distal, but devoid of median

lateral spine. Left P5 in male with finger- or thumb-shaped process and inner seta apically.

Ranga Reddy (1987) divided the genus Allodiaptomus into two subgenera and defined them

as follows:

1. Subgenus Allodiaptomus s. str. Kiefer, 1936

First exopodal segmentof legs 1-4 with outer marginal spine; third endopod-segment of legs 2-4

with 2 outer marginal setae (total 7 setae). Proximal lateral spine of second exopodal segmentof

male right P5 articulated to the margin.

2. Subgenus Reductodiaptomus Ranga Reddy, 1987

First exopodal segment of legs 1-4 without outer marginal spine; third endopod-segment

of legs 2-4 with 1 outer marginal seta (total 6 setae). Proximal lateral spine on second exopodal

segmentof male right P5 articulated to posterior face.

75

Type species: *Allodiaptomus (Allodiaptomus) mirabilipes Kiefer, 1936

Other valid species in the genus Allodiaptomus following Ranga Reddy et al., 2000

*Allodiaptomus (Allodiaptomus) intermedius Ranga Reddy, 1987

*Allodiaptomus (Allodiaptomus) satanas (Brehm, 1952)

Allodiaptomus (Allodiaptomus) rarus Ranga Reddy, Sanoamuang & Dumont, 1998

Sub genus: Reductodiaptomus Ranga Reddy, 1987

Type species: *Allodiaptomus (Reductodiaptomus) raoi Kiefer, 1936

In the present study, I came across the asterisked of the above species.

Key to the females of Indian Allodiaptomus spp.

1. First exopodal segmentof legs 1-4 with outer marginal spine; third Endopod-segment of

leg 2-4 with 7setae…………………………………………………Allodiaptomus s. str…..2

First exopodal segment of legs 1-4 without outer marginal spine; third Endopod-segment of

legs 2-4 with 6 setae……………………………….…..subgenus Reductodiaptomus A. (R) raoi

2. Posterior border of fifth pediger devoid of spinules; right metasomal wing rounded and much

smaller than left wing; endopods of fifth legs 1 segmented…………….…………………….3

Posterior border of fourth pediger devoid of spinules; right metasomal wing bilobed and

slightly smaller than left wing; endopods of fifth legs 2-segmented ………..…..A. (A) satanas

3. Left genital spine triangular and posteriorly directed ; second urosomite short, being 11% or

urosome length; right or left coxal spine in fifth legs about 0.7 times as long as endopod of

same appendage……………………..…………………………………….A. (A) intermedius

76

Left genital spine acicular with triangular apex and posterolaterally directed; second urosomite

long, being 2.5 times of Urosome length; right or left coxal spine in fifth legs not more than 0.3

times as long as endopod of that appendage………..……………………………...(A.) mirabilipes

Key to the males of Indian Allodiaptomus spp.

1. First exopod-segments of legs 1-4 with outer marginal spine; third endopod-segment of

legs 2-4 with 7 setae…………………………………………subgenus Allodiaptomus s. str.

First exopodsegment of leg 1-4 without outer marginal spine; third endopod segment of legs 2-4

with 6 setae…………………………………………subgenus Reductodiaptomus A. (R.) raoi

2. Antepenultimate segment of grasping antennule produced into short comb-like spinous

process; left P5 with 2 digitiform apical structures plus unjointed seta ………A. (A.) satanas

Antepenultimate segment of grasping antennule produced into short slender spinous process

that extends a little beyond mid-length of succeeding segment; left P5 with single digitiform

structure plus jointed seta…………………………………………………………………….3

3. Second exopodal segmentof right P5 with 3 outer lateral spines and rounded projection at

about mid-inner margin ……………………………………………………….A. (A.) mirabilipes

Second exopodal segmentof right P5 with 2 outer lateral spines and smooth inner

margin……………………………………………….……………..…………..A. (A) intermedius

77

Allodiaptomus (Allodiaptomus) mirabilipes Kiefer, 1936

(Figs 47-49, Pl. 19)

Allodiaptomus mirabilipes Kiefer, 1936a: 139-141, Figs 9-11. [♂ only; ♀ = Heliodiaptomus

cinctus (Gurney)]; Kiefer, 1936c: 323-325, Figs 16-17 (♀); Brehm, 1953: 253-256, Figs 12-16;

Abraham, 1972: 252-257, Figs 8-10, 24-25.

Allodiaptomus (Allodiaptomus) mirabilipes: Ranga Reddy, 1987: 119-122, Figs 31-41; Ranga

Reddy, 1994: Figs 123-132.

Type locality: An unspecified locality in Karnataka (formerly Mysore) State, South India.



Female

Left metasomal wing ovate, extending right up to base of left genital spine. Genital

double-somite much dilated proximally; left genital spine acicular with triangular apex, arising

on short projection, and directed posterolaterally; right spine narrow, straight and set at right

angle to somite; somite indented laterally beyond genital aperture. Caudal rami symmetrical, 1.6

times as long as wide, and generally with hirsute lateral margins; in some populations, hair only

on outer margins, this showing inter population variation (Fig. 47g). P5: Coxal spine slender and

arising from a lobe-like structure. Basis with short sensory seta. Third exopodal segment

represented by 1spine and 1 seta; size of spine showing variation. Endopod over 2/3 as long as

first exopodal segment; apex obliquely truncate.

Male

Fourth and fifth pedigers demarcated by transverse row of delicate dorsal spinules. Caudal

rami nearly symmetrical, 1.7 times as long as wide and without hairs. Grasping antennule with

78

spine on each of segments 8 and 10-16; spine on segments 13 and 16 longer than depicted by

Kiefer (1936a); spinous process on antepenultimate segment 0.6 times as long as succeeding

segment, straight, with hooked tip or sometimes 2 small apical teeth. P5: right P5 with coxa

produced into obtriangular lobe at distal inner corner; basis with 1 elongate and proximally-

digitate hyaline lamella on inner margin; the shape lamella varying in some populations; first

exopodal segment produced into pointed spinous process at distal outer corner; second segment

highly unique, with its armature consisting of 2 principal lateral spines, 1 small accessory spine

at the base of outcurved proximal lateral spine and another accessory spine between distal lateral

spine and end claw; inner margin with characteristic chitinous plug at about midlength; length

and curvature of the proximal lateral spine showing interpopulation variation; end claw strong,

greatly varying in shape. Endopod short, 1.4 times as long as maximum width at base and barely

reaching chitinous plug. Left P5: Basis with small hyaline lobe at mid-inner margin. Endopod

cylindrical, hardly reaching posterior border of first exopodal segment.

Remarks

Regarding the morphology of A. (A.) mirabilipes, it is noteworthy that the end claw of

the male right P5 is subject to extraordinary variation in size and shape. Another remarkable

feature is that whereas the caudal rami are hairy along outer and inner margin of female, they are

bare in male. On the whole this species is hightly variable.

Ecology

A. mirabilipes is the most common and endemic species in Kerala, occurring in rice

fields, ponds (including temple ponds) fed by surface run-off from nearby rice fields or irrigation

canals. Water temperature 26-30ºC, pH 6.5-8.0, Secchi transparency 17-89 cm. It was found in

rivers in Kerala: Bharathpuza, Muvattupuzha, Kundu and Periyar. It does not occur in isolated,

79

solely rain-fed, temporary or permanent water bodies. Abraham (1972) reported it from Cochin

Backwaters ―during monsoon period when the salinity of the water was very low bearing fresh

condition. In the present study it was found in good numbers in brackish habitats. It was found

co-occurring with H. viduus and P. sasikumari.

Distribution

A. mirabilipes is the sole representative of Allodiaptomus and endemic in Kerala;

its putative occurrence in Karnataka and Tamilnadu (see Ranga Reddy 1994) is questionable.

Previous records

It was reported from Quilon, Trivandrum and Ernakulam (Brehm, 1953) and

Cochin Backwaters (Abraham, 1972) in Kerala, an unspecified locality in Karnataka (Kiefer,

1936a,) and Madras in Tamilnadu.

Present records

In the present survey A. mirabilipes was met in good numbers in several habitats at

Trichur, Shornur, and Cherpelchery of Kerala State. For distribution, see map (Fig. 49).

Conservation Status: Risk (LR Lower).

Allodiaptomus (Allodiaptomus) intermedius Ranga Reddy, 1987

(Figs 50-52, Pl. 20)

Allodiaptomus (Allodiaptomus) intermedius: Ranga Reddy, 1987: 42-80; 1994: 133-147;

Ambedkar, 2005: 39-41, Figs 1-9.

Type locality: Pond at Dharmavaram, Anantapur district, South India.


Body size. Female 0. 64-1.12 mm; male 0. 8-0.95 mm.

80

Female

Fourth and fifth pedigers separated by transverse row of spinules on dorsal surface.

Metasomal wings strongly asymmetrical as in A. mirabilipes; right wing small, evenly curved

with 2 almost similar spines, 1 dorsal and 1 lateral; left wing generally ovate with attenuated

apex, and extending up to base of left genital spine. Left wing showing inter-population

variation. Urosome composed of 3 somites; genital double-somite as in A. mirabilipes except

right genital spine being shorter and left spine undilated and posteriorly directed. Right caudal

ramus slightly wider than left ramus; each ramus 1.4 times as long as wide, with fine hairs along

both margins. P5: left coxal spine longer than its counterpart. Third exopodal segment

represented by 1 spine and 1 seta. Endopod cylindrical, slightly shorter than first exopodal

segment with spinules at the apex.

Male

Fourth and fifth pedigers, as in female, separated by transverse row of spinules.

Metasomal wings symmetrical, short, rounded, each wing with lateral spine; spine on right wing

slenderer. Posterior part of urosome slightly bent to right side. Genital somite with spine at right

posterior corner, and indented at left posterior corner. Margins of caudal rami without hairs.

Right antennule with spine on each of segments 8 and 10-16; spinous process on antepenultimate

segment as in Fig. 51f-i, Pl. 12d, e. P5: right P5 coxa produced into bifid lobe at inner distal

corner; basis with elongate, hyaline membrane on inner margin; first exopodal segment drawn

out in to short, pointed spinous process, second exopodal segment cylindrical, with 2 outer

lateral spines; proximal spine marginal in position; a broad, hyaline lobe lying at base of

proximal spine; distal lateral spine pointed, hardly reaching the base of end claw; sometimes a

small chitinous lobe, lying between distal spine and end claw; end claw sickle shaped, slightly

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thickened at midlength, with finely spinulose inner margin. Endopod pyriform, apex rounded.

Left P5: coxa nearly rectangular with small hyaline spine towards distal inner corner; basis wider

than long, with somewhat elongate, hyaline lamella on inner margin; exopod indistinctly 2-

segmented. Endopod cylindrical, with incipient cross septum halfway.

Remarks

The female left metasomal wing, the orientation of spines on the genital double-somite,

coxal spines and end claw on P5 of female are somewhat variable. On male geniculate antennule,

segment 13 and spinous process on antepenultimate segment; coxal lobe as well as distal lateral

spine on right P5 of male are also variable. The unique features of A. intermedius include: the

left genital spine is posteriorly directed; on male right P5, coxa is produced into a bifid hyaline

lobe at the distal inner corner, the second exopodal segment cylindrical, 2.6 times as long as

wide, and of the two outer lateral spines borne by it, the proximal one is much stronger, dilated at

the base, fused to the segment and 3/5 the length of the same segment, whereas the distal spine

is small and blunt.

Ecology

A. intermedius was collected in tanks, ponds in rice fields and coffee plantations and open

wells, in which the water temperature range was 21ºC-30˚C, and pH 7.0. It was also reported

from rocky ponds at elevated places, i.e. Bababudangiri (alt. 1355 m) (Ranga Reddy, 1994). In

present study it has been collected in turbid village tanks and reservoirs in which the temperature

rane was 20-33ºC, pH 7.5-8.5, Secchi transparency 11-66 cm. A. Intermedius was accompanied

by H. viduus, N. lindbergi and H. cinctus on different occasions (see Material examined).

82

Distribution.

A. intermedius was originally reported from Dharmavaram and Cumbum tank in Andhra

Pradesh State (Ranga Reddy, 1987). Ranga Reddy (1994) found it in irrigation canals and canal-

fed ponds in Kurnool district of Andhra Pradesh and at the following localities in Karnataka

state: Kamalapuram tank, Gowramma pond and Ramsagar tank around Hospet, Kartikera and

Magadi tank on the way to Belur from Chickmagalur, small pond at Deverajpura, 4 km from

Belur, Bababudangiri (Dattathreyapeetha), a pond beside Vasanta Cool Estate, 3 km from

Chickmagalur, an open circular well near Agricultural Implements Industry, Chickmagalur. In

the present investigation, I have found this to be the most common allodiaptomid in Cumbum,

Nandyal, Banaganapalli, Avuku and Tadipatri in Andhra Pradesh. For distribution, see map (Fig.

52).

Conservation Status: Vulnerable (VU B2).

Allodiaptomus (A.) satanas (Brehm, 1952)

(Figs 53-54, Pl. 21)

Type locality: Soukna Lake, Panjab, India.

Body size. Female 1.5mm; male 1.3-1.6 mm.

Female

Fourth and fifth pedigers without dorsal spinular row between them. Lateral wings small

and asymmetrical, left wing narrow somewhat triangular while right wing relatively wide, round

and bilobed. Genital somite longer than rest of urosome including caudal rami, almost

symmetrical, proximal part dilated and armed with small hyaline spine on each side. Caudal rami

1.5 times as long as wide. Antennules extending to the tips of caudal setae. P5: coxal spines of

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both legs small and equal. Third exopodal segment small but distinct, with 2 very unequal spines.

Endopod 2-segmented, surpassing 2/3 length of first exopodal segment; apex round.

Male

Spine at right distal corner of genital somite reaching midlength of succeedig somite;

second and third urosomites with ventral hairs. Caudal rami nearly twice as long as wide,

asymmetrical; right ramus with 2 chitinous small prominences on distinctly convex proximal

outer margin and 2 large stumpy teeth on ventral side; third seta of this ramus stouter than the

rest. Right antennule with spine on each of segments 8 and 10-15; spinous process on

antepenultimate segment short, comb-like with 3-5 teeth. P5: coxa produced into broad lobe at

distal inner corner. Basis with prominent horn-like outgrowth, lying perpendicular to the long

axis of the segment, at proximal inner margin. Second exopod segment with 2 lateral spines:

proximal spine long and S-shaped; distal spine short and unarticulate; inner margin with a ledge

opposite to origin of proximal lateral spine. Endopod roughly spindle-shaped and extending to

ledge of second exopodal segment. Left P5: Second exopodal segment with 2 digitiform

structures flanking 1 unjointed seta. Endopod strong and slightly longer than first exopodal

segment.

Ecology

A. satanas is rarest among the Indian allodiaptomids. It appears to be commonly restricted

to large, permanent water bodies like lakes.

Distribution

A. satanas is endemic to north and northeastern India. It was reported from Soukna

Lake in Panjab State (Brehm 1952), and Tasek Lake, Chitmareng Lake and nursery fish ponds in

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Garo Hills of Meghalaya State of India (Ranga Reddy & Das, 1981). Also, see map for

distribution (Fig. 54).


Allodiaptomus (Reductodiaptomus) raoi Kiefer, 1936

(Figs 55-57, Pl. 22)

Allodiaptomus raoi Kiefer, 1936a: 137-139, Figs 1-6; Devi & Ranga Reddy, 1989b: 264- 265,

Figs 41-42, 80, 83.

Allodiaptomus raoi var. membranigera: Brehm, 1951: 100, Figs, 8-11.

Allodiaptomus specillodactylus: Shen & Tai, 1964: 234-235, Figs 26-33.

Allodiaptomus (Reductodiaptomus) raoi; Ranga Reddy, 1987: 114-119, Figs 1-30; Ambedkar,

2005: 42-45, Figs 1-7.

Type locality: Nellore, South India.

Body size. Female 0.8 -1.2 mm; male 0.8-1.0 mm.

Material examined: as in Table12.

Female

Body slender. Fourth and fifth pedigers demarcated by a transverse row of dorsal

spinules. Lateral wings of fifth pediger asymmetrical, left wing being longer that of right one.

Genital double-somite elongate but proximally less dilated than in A. mirabilipes and A.

intermedius; both spines drawn over dorsolateral margin of genital double-somite and directed

posterolaterally; right spine varying in size as illustrated in Fig. 55 b,c. Caudal rami 1.9 times as

long as wide. P1-P4: First exopodal segment of P1-P4 without outer marginl spine; third

endopod segment of P2-P4 with 6 setae. P5: coxal spine of left leg distinctly larger than that of

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rightP5. Basis with elongate sensory seta extending beyond the midlength of first exopodal

segment. Third exopodal segment represented by 1 spine and 1 seta. Endopod narrow,

cylindrical, slightly shorter than first exopodal segment; apex abliquely truncate with a row of

fine spinules.

Male

Fourth and fifth pedigers separated by transverse row of delicate spinules. The structure

of right antennule as illustrated in the Fig. 56c-i, Pl. 22b, c. Right P5: Coxa produced at distal

inner corner into broadly triangular lobe. Basis with elongate hyaline lamella midway on inner

margin. Second exopodal segment with 2 lateral spines; proximal spine long, articulated to the

posterior face, distal lateral spine shorter than the proximal spine, typically marginal and

posteriorly bent. A flat hyaline lobe lying obliquely at the base of proximal spine. Endopod

proximally dilated and slightly more than half as long as second exopodal segment. Left P5:

Basis with 1 hyaline lobe at distal inner corner. Endopod indistinctly 2-segmented.

Remarks

The coxal spine on the left P5 in the female, the two lateral spines on the second

exopodal segment, and the endopod of the P5 in the male are variable.

A. raoi can be readily distinguished by the following characters: Body relatively more

slender than in other species. In female, the left metasomal wing is short with rounded apex,

barely reaching the left genital spine; the genital double-somite is less dilated proximally, with

its both spines lying on the dorsolateral surface; the caudal rami are longer; the natatory legs,

mandibles and maxillulae have reduced armature; in female, coxal spine on right P5 is much

smaller than on left P5. On male P5, the second exopodal segment of the right P5 is twice as long

86

as the basal width, with its proximal lateral spine almost straight and drawn over its posterior

face and generally over twice the length of the distal lateral spine; the endopod is tubular and

half as long as second exopodal segment. The coxa is produced into a broadly triangular, hyaline

lobe at its distal inner corner; the second exopodal segment of the left leg has a roughly

lanceolate outer process and unjointed inner seta.

Ecology

A. raoi is common in slow-flowing waters, fish ponds and reservoirs of Guntur and

Krishna Districts in Andhra Pradesh State, South India (surface water temperature 26-37ºC; pH

6.5 - 8.0). It is present almost throughout the year in River Krishna at Vijayawada, often co-

occurring with Pseudodiaptomus binghami (Ranga Reddy & Radhakrishna, 1982). A.raoi is the

most common diaptomid and it is well adapted to the lentic conditions of ricefields, ponds,

reservoirs and lakes (Lake Kolleru), which are directly fed by the river Krishna. It appears to be

most rheophil of all Indian diaptomids. A. raoi is amenable to cultivation under laboratory

conditions. According to Devi & Ranga Reddy (1989b) who raised this speicies from its eggs, it

completes naupliar phase in 7 days and copepodid phase in 8 days at a room temperature of

26ºC-31ºC. It co-occurs with H.viduus, N. lindbergi and H. contortus on different occasions.

Distribution

Previous records

A. raoi has so far been reported only from two places outside India viz., Tonle Sap in

Camboida (Brehm, 1951) and Chulapore reservoir in Thailand (Bricker et al., 1978) and South

China. In India it is known from Nellore (Kiefer, 1936a), River Tapti near Mandi (Brehm, 1953),

87

Madurai, Calicut, Bangalore, Balabadrapuram, and from unspecified localities in Gujarat and

Tripura States.

Present records

In present study, A. raoi was found in a host of diverse habitats in the deltaic region of

River Krishna. And also recorded as a common species in the habitats of Guntur: Uppalapadu,

Tadikonda (temple pond), Nidumukkala, Amaravati, Jonnalagadda, Gorantla, Chuttagunta, Kaja,

Kantheru, Nidamarru, Mangalagiri, Koppuravuru, Vadlamudi, Vaikuntapuram, Etukuru,

Prattipadu, Pedanandipadu, Bapatla; Prakasam district: Parchuru, Inkollu, Kolapudi,

Thativaripalem, Bollapalli, Konanki, Martur, Kotappa Konda, Vinukonda, Santhamaguluru,

Chirala, Ongole, Medaramitla, Mattigunta, Chinna Ganjam; Nellore district: Bodigrithota,

Kakupally, Krishnapatnam. For distribution, see map (Fig. 57).

Conservation Status: Lower Risk (LR).

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Genus Neodiaptomus Kiefer, 1932

Neodiaptomus: Kiefer, 1932a: 474; Brehm, 1933: 135; Kiefer, 1939: 126; Shen & Song, 1979:

138; Lai & Fernando, 1981: 163; Ranga Reddy & Das, 1981: 8; Dussart & Defaye, 1983: 94;

2002; 117; Borutzky et al., 1991: 424; Ranga Reddy & Subba Reddy, 1992: 125; Ranga Reddy

1994: 43; Dussart, B.H. & D. Defaye, 2002: 117.

Generic diagnosis

Kiefer‘s (1932c) original definition of the genus Neodiaptomuss has been revised by

Ranga Reddy (1994) as follows: Animals of moderate size (1.1-1.5 mm). Female: antennules

long, extending beyond caudal setae. Fifth legs mostly asymmetrical. Coxal spines strong; end

claws generally with coarsely denticulate margins; third exopodal segment reduced or absent,

represented by 2 unequal spines; apex of endopod obliquely cut on inner margin, pointed and

without setae. Male: right antennule with spine on each of segments 10, 11, 13-15;

antepenultimate segment with long or sometimes short spinous process. On right P5, coxa

produced into somewhat triangular, pointed or bifid lobe (inter coxal plate) at distal inner corner;

endopod long, 1-segmented, dilated at base and attenuating apically (pyriform); lateral spine

inserted generally at the middle of outer margin of second exopodal segment. Right caudal ramus

with tooth-like chitinous structure at inner ventro-distal corner.

Type species: *Neodiaptomus schmackeri (Poppe & Richard, 1892)


*Neodiaptomus physalipus Kiefer, 1935

* Neodiaptomus lindbergi Brehm, 1951

*Neodiaptomus intermedius Flößner, 1984

89

*Neodiaptomus meggitti Kiefer, 1932

Neodiaptomus lymphatus Brehm, 1933

Neodiaptomus yangtsekiangensis Mashiko, 1951

Neodiaptomus laii Kiefer, 1974

Neodiaptomus blachei Brehm, 1951

Neodiaptomus botulifer Kiefer, 1974

Neodiaptomus mesphistopheles Brehm, 1933

Neodiaptomus vietnamensis Dang & Ho, 1998

Neodiaptomus songkhramensis Sanoamuang & Athibai, 2002

Neodiaptomus siamensis Proongkiat & Sanoamuang, 2008

Of the species listed above, the asterisked ones are known from India.

Key to the females of Indian Neodiaptomus spp.

1. Second inner terminal seta of right caudal ramus sharply directed laterally, crossing over

third seta…………….…………………………………..………………………..N. intermedius

Second and third terminal setae of right ramus parallel to each other………....……………….2

2. Lateral wings of the fifth pediger distinctly wide; left wing only slightly longer than right wing

and with depressed posterior border; apex of endopod obliquely truncated...………N. lindbergi

Lateral wings of fifth pediger relatively narrow; left wing longer than the right and with

rounded or straight posterior border; apex of endopod nearly rounded……………N. physalipus

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3. Urosome of 2 somites; genital double-somite nearly symmetrical, shorter than second

urosomite plus caudal rami; right proximal protrusion of the same somite inconspicuous and

with only 1 spine; 3rd

and 4th

caudal seta fused at the proxima portion……………...N. meggitti

Urosome of 3 somites; genital double-somite strongly asymmetrical, longer than other 2

urosomites plus caudal rami; right proximal protrusion very conspicuous and generally

with 2 spines; caudal setae proximally dilated and bent…………………………..N. schmackeri

Key to the males of Indian Neodiaptomus spp.

1. Ventral tooth-like process of right caudal ramus very large, half as long as ramus; on P5, inter

coxal plate wedge-shaped; subproximal enlargement of end claw on right P5 ―skull-shaped‖ or

broadly conical…………………………………………………………………..N. intermedius

Ventral tooth-like process less than half the length of ramus; on P5 inter coxal plate conical;

subproximal enlargement of end claw on right leg 5 bulbous………...………..………………2

2. Basis with crescentic hyaline lobe on inner margin and longitudinal chitinous fold on posterior

surface; on right P5, endopod less dilated at base and almost conical; on left P5, coxa with

large, chitinous outgrowth at distal outer region…………...………...………………N. meggitti

Basis with roundish hyaline lobe on inner margin, but without longitudinal chitinous fold on

posterior surface; on right P5, endopod much dilated at base and bottle-shaped; on left P5

coxa without any chitinous outgrowth at distal outer region…………………..N. physalipus

3. Right caudal ramus with moderate, tooth-like chitinous process and with 2 chitinous

91

projections near its base…………………………………………………………….N. lindbergi

Right caudal ramus with very small, triangular tooth-like chitinous process and with no

chitinous projections near its base………………………………………………..N. schmackeri

Neodiaptomus schmackeri (Poppe & Richard, 1892)

(Figs.58, 59, Pl. 23)

Diaptomus schmackeri: Poppe & Richard, 1892: 149-151, Figs 1-6; Rylov, 1925: 315; Kiefer,

1928: 106-109, Figs 20-22.

Neodiaptomus schmackeri: Kiefer, 1932a: 475, 509, Fig. 87; Kiefer, 1939:121-126, Figs 11-12;

Rajendran, 1971: 92-99, Figs 1-2; Shen & Song, 1979: 139-141, Figs 71a-i; Lai & Fernando,

1981: 165, Figs 24-35; Subba Reddy, 1989: 17-26, Figs 1-45; Bhattacharya et al., 1990: 73-78;

Borutzky et al., 1991: 426-427, Fig. 189; Ranga Reddy & Subba Reddy, 1992: 125, Fig. 1;

Ranga Reddy 1994: Figs 198-215; Dussart & Defaye, 2002: 117; Ambedkar, 2005: 46-48, Figs

1-10.

Diaptomus strigilipes: Gurney, 1907: 30-31, P1.2, Figs 18-20.

Neodiaptomus strigilipes: Brehm, 1953: 258-263, Figs 20-23; Dumont & Van de Velde, 1977:

62, Figs 410 g-k;Ranga Reddy & Radhakrishna, 1984: 28; Dussart & Fernando, 1985: 232-233,

Figs15-21.

Neodiaptomus strigilipes var. parvidens: Brehm 1953: 265.

Diaptomus handeli: Brehm, 1921: 1921-195; Rylov, 1925: 313-314, Figs 8-13.

92

Neodiaptomus handeli: Kiefer, 1932a: 475, 509; Mashiko, 1951: 144-145, Figs 3a-j; Uèno, 1966:

105-107, Figs 44-59; Lai & Fernando, 1978a: 113-115, Figs 1-8; Rajendran, 1979b: 49-52, Figs

1-2; Dussart & Fernando, 1985: 232-234, Figs 8-14.

Neodiaptomus bisegmantus: Hu, 1943: 115-118, Figs A, 1-7.

Type locality: Lake Tahoo, China.


Body size: Female 0.9-1.7 mm; male 0.9-1.4 mm.

Female

Lateral wings well developed and asymmetrical. Genital double-somite asymmetrical,

almost as long as its maximum width; subproximal part dilated into a lobe on each side. Caudal

rami 1.4 times as long as wide, with hirsute inner margins. P5: coxal spines of both legs almost

equally large and arising directly from the segments. Right end claw with 6-8 denticles on inner

margin and 0-6 on outer margin. Left end claw with 8-11 denticles on inner margin and 0-4 on

outer margin. Third exopodal segment distinct. Endopod 1-segmented, shorter than first

exopodal segment.

Male

Caudal rami almost symmetrical; right ramus with small chitinous tooth at inner distal

corner on ventral surface; right antennule with spine on each of segments 8 and 10-15; spines on

segments 8, 12, and 15 very short; spinous process on antepenultimate segment straight, as long

as or slightly longer than succeeding segment, with generally hooked tip. Right P5: coxa with

roughly bifid hyaline lobe at distal inner corner. Lateral spine of second exopodal segment

generally shorter than the segment and lying at midlength of its outer margin. End claw sickle-

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shaped and somewhat thickened subproximally. Endopod flask-shaped. Left P5: Basis with

roundish hyaline lamella on inner margin. Endopod vaguely two segmented.

Remarks

N. schamackeri as the type-species of the genus Neodiaptomus is the oldest known and

most confused taxon. Inaccurate depiction of this species from different parts of Asia by several

earlier workers has led to a great deal of taxonomic confusion. According to Ranga Reddy &

Subba Reddy (1992), the female caudal setae are highly diagnostic of this species, being dilated

proximally and distinctly curved. As for the males, the bilobed inter-coxal plate of right P5, the

subproximal thickening of the end claw on right P5 and the conspicuously small, tooth-like

process present at the ventro-distal inner corner of right caudal ramus can easily help separate N.

schmackeri from all the known congeners.

A close scrutiny of the material under examination has revealed that the species is subject

to inter- and intra-population variation in several characters such as the form of metasomal wings

and genital double-somite in female and its spines, and the spinous process on antepenultimate

segment of grasping antennule and inter-coxal plate on right P5 of male. The lateral spine on

second exopodal segment of the male right P5 is also somewhat variable: it is either shorter than

the segment as observed by Ranga Reddy or as long as the same segment (see Pl. 23d).

Distribution

Previous records

Among the various Neodiaptomus spp., N. schmckeri is most widely distributed India

and Southeast Asia including China, Thailand, Sri Lanka, Nepal, Bangladesh, Malaysia,

Singapore, Thailand, Philippines and east Siberia. It is distributed throughout India, having been

94

recorded from several northern and southern States: Assam, Bihar, (Gurney, 1907; Brehm,

1953), West Bengal (Sewell, 1924, 1934; Brehm, 1950; Rajendran, 1973), Madhya Pradesh and

Uttar Pradesh (Brehm, 1950), Orissa (Sehgal, 1967), Karnataka (Brehm, 1950), Tamilnadu

(Brehm, 1953; Rajendran, 1971, 1973), Kerala (Pillai, 1971), Andhra Pradesh

(Brehm, 1953; Ranga Reddy, 1977).

Present records

As in Material examined.

Ecology

N. schmackeri is dominant in hillpools (Guntur environs) in which the water

temperature ranged from 22 to 30 ºC, pH 6.5-7.5 and Secchi disc transparency 40-150 cm. In

India, N. schmackeri is mostly confined to ephemeral, turbid, fresh water pools and ponds of

plains rather than permanent habitats. Its occurrence in large water bodies like lakes is rare. It

was not found it in rivers or canals. It appears to be a predominantly freshwater, stenotopic

species. It often co-occurs with H. viduus, P. blanci or M. pseudohebes. Generally N.

schmackeri has not been accompanied by any of its congeners except on a single occasion when

it did it co-occur with N. intermedius.

Conservation status. Lower Risk (LR); Least Concern (lc).

95

Neodiaptomus physalipus Kiefer, 1935

(Figs 60-62, Pl.24)

Neodiaptomus physalipus: Kiefer, 1935: 117-119, Figs 11-16: Kiefer, 1939: 116-119, Figs 9a-f;

Brehm, 1953: 268-269, Figs 30-33; Ranga Reddy & Subba Reddy, 1992: 125-126, Figs 2-20;

Ranga Reddy, 1994: Figs 216-235; Dussart & Defaye, 2002: 118.

Neodiaptomus physalipus diaphorus: Kiefer, 1935: 119-120, Figs 17-18.

Neodiaptomus diaphorus: Kiefer, 1939: 119-121, Figs 10a-h; Rajendran, 1973: 127, 136, Figs

1a-1; Flößner, 1984: 262; Subba Reddy, 1989: 36-44, Figs 1-50.

Neodiaptomus tiwarii: Roy, 1984a: 101-108, Figs 1a-h.

Type locality: Small pond in swamp at Ootacamund, Nilgiri Hills, South India.

Material examined: 3 males, 3 females; pond at a Garden pit, Kodaikanal (9°48′ 0″ N,

78° 6′ 0″ E; altitude of 2225 m), 27 October, 2004, leg. Y. Ranga Reddy.


Female

Left wing of fifth pediger slightly larger than right wing and extending up to left genital

spine or nearly so. Genital double-somite asymmetrical, slightly longer than its own maximum

width and also longer than rest of urosome including caudal rami; subproximal part dilated with

2 unequal, variable spines on right side and 1 spine on left side. Caudal rami alike in dorsal view,

1.5 times as long as wide with hairy inner margins. Antennules reaching beyond caudal setae by

last 2 or 3 segments. P5: coxal spines almost equal in size. Sensory seta on basis reaching about

midlength of first exopodal segment. Inner and outer margins of end claw lined with denticles.

Third segment distinct. Endopod slightly shorter than first exopodal segment.

96

Male

Second and third urosomites with hairy ventral margin. Right caudal ramus larger than

left ramus, and ventro-distal inner corner with distinctly large tooth-like chitinous process, 0.4 as

long as its ramus. Right antennular segments 8 and 10-14 with a spine each; segment 15 with a

short spine; spinous process on antepenultimate segment almost staff-like, generally longer than

penultimate segment, with hook-like tip; sometimes tip normal or blunt. P5: intercoxal lobe

roughly conical with blunt tip. Basis with 1 spherical hyaline lobe on inner margin; lateral spine

of second exopodal segment lying at midlength of outer margin and as long as or slightly longer

than the segment; end claw sickle-shaped; subproximal outer region with bulbous enlargement,

with rounded or flat outer margin. Endopod bottle-shaped and stouter than second exopodal

segment. Left P5: Basis without hyaline lamella on inner margin. Other details as illustrated.

Remarks

The inter- and intra-population variation manifest in the wings of the fifth pediger of

female, and the spine of the 15th

segment and the spinous process on the antepenultimate

segment of the grasping antennules has led to the synonymisation of N. diaphorus with N.

physalipus (see Ranga Reddy & Subba Reddy, 1992). The large chitinous structure on the right

caudal ramus, the proximal enlargement of the end claw of right P5 and spinous process on the

right antennules in male are highly diagnostic of the species.

Ecology

Reported from Ooty Lake, Pykara dam, vegetation-infested pools and ponds near Pykara

in Nilgiri Hills at an altitude of 2225 m within a temperature range of 16- 19 ºC and pH of 6.6.

Distribution

97

N. physalipus is endemic to certain hills of South India. For distribution, see map (Fig.

62).

Conservation status: VU B1.

Neodiaptomus lindbergi Brehm, 1951

(Figs. 63-65, Pl. 25)

Neodiaptomus lindbergi: Brehm, 1951a: 158-160, Figs 1-6; Brehm, 1953: 264-268, Figs 24-29;

Ranga Reddy, 1977; 66-70, PI. 10, Figs 1-11; Subba Reddy, 1989: 51-59, Figs 1-52; Ranga

Reddy & Subba Reddy, 1992: 127-128, Figs 22-52; Ranga Reddy, 1994: Figs 236-268;

Ambedkar, 2005: 48-50, Figs 1-13.

Neodiaptomus sewelli: Roy, 1984a: 133-138, Figs 1a-h.

Type locality: Pondicherry, South India.



Female

Genital double-somite longer than its own width as well as rest of the urosome including

caudal rami, asymmetrical and dilated subproximally; left side with 1 spine arising from narrow

lobe-like projection; rightside with 1 spinous projection and 1 short spine. Caudal rami with

hairy inner margins; basal part of right ramus expanded and lamellate in lateral view. P5: coxal

spine slightly dilated proximally; sensory seta of basis reaching beyond midlength of first

exopodal segment. End claw with denticulate margins. Endopod nearly as long as first exopodal

segment.

98

Male

Second and third urosomites fringed with ventral hairs. Right caudal ramus armed with

relatively large, tooth-like structure at ventro-distal inner corner and also with 2 small chitinous

projections near base of this structure. Right antennule with spine on each of segments 8 and 10-

16; spinous process on antepenultimate segment straight or somewhat curved and longer than

penultimate segment. Right P5: intercoxal hyaline plate nearly triangular; basis with crescentic

hyaline lobe on inner margin; lateral spine of second exopodal segment lying at about the middle

of outer margin and somewhat longer than, or just equal to, the segment; end claw elongate,

slender, sickle-shaped and without any proximal thickening. Endopod bottle-shaped and

extending beyond midlength of second exopodal segment. Left P5: Basis with 1 hyaline lobe

near inner distal corner.

Remarks

N. lindbergi displays a strong affinity to N. physalipus and N. intermedius especially in

regard to lamellate nature of the right caudal ramus. However, the shape of left metasomal wing

and the apex of endopod of P5 show subtle but valid differences between these species. The

males of those species, on the contrary, are quite distinct. The end claw of right P5 in male

appears to be alike in N. lindbergi and N. schmackeri superficially. A close observation of the

same, however, reveals a subtle but highly valid difference, i.e. the end claw invariably has a

slight thickening on the proximal inner margin in N. schmackeri and no such feature in N.

lindbergi.

The present study, as also the published reports (Ranga Reddy & Subba Reddy, 1992,

Ranga Reddy, 1994), clearly shows that the following characters are somewhat variable: the

wings on fifth pediger of female, the spines on the female genital double somite, the spines on

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segments 15 and 16, and the spinous process on the antepenultimate segment of the grasping

antennule, the inter-coxal plate and spinous projection of first exopodal segment on right P5 of

male, the shape of the endopod of male right P5, and the form of the chitinous tooth on male

right caudal ramus.

Distribution

Previous records

N. lindbergi is endemic to peninsular India, where it is widely distributed. None of the

samples from North India have yielded this species. This is the sole neodiaptomid found in the

majority of the samples collected from Karnataka during this study. Previous records. Pondi,

Mourabas, Phandharpur, Kurdu and Dharwar Guntur, Acharya Nagarjuna University campus and

Timmasamudram (Ranga Reddy 1977).

Present records

Tadikonda, Yanamadala and Kaja in Guntur district; Prakasam: Ongole, Giddalur,

Akaveedu and Kolalapoodi village in Prakasam district of Andhra Pradesh.

Ecology

Like Neodiaptomus schmackeri, this species generally prefers ephemeral, turbid

freshwater ponds and pools of the plains. It was never found in large clear water bodies like lakes

and reservoirs. This speices was collected when the water temperature was 24ºC-36ºC, pH 7.0-

8.5 and Secchi disk transparency 11-65.5 cm. It often co-occurred with A. intermedius, H.

viduus, S. indicus and P.blanci.

Conservation Status: VU C2

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Neodiaptomus intermedius Flößner, 1984

(Figs 66-68, Pl. 26)

Neodiaptomus diaphorus: Ranga Reddy, 1977: 58-63, P1.9, Figs 1-13.

Neodiaptomus intermedius: Flößner, 1984: 259-263, Figs 1-20; Subba Reddy, 1989: 67-76, Figs

1-40; Ranga Reddy & Subba Reddy, 1992: 129, Fig. 21; Ranga Reddy, 1994: Figs 269-

285.118.

Type locality: Reservoir in the adjacent lowland of the Niligiri Hills, South India.


Body size. Female 0.8-1.8 mm; male 0. 8-1.4 smm.

Female

Metasomal wings well developed and asymmetrical; each wing armed with 2 small

unequal hyaline spines. Genital double-somite longer than rest of urosome. Genital structures as

in Pl. 26b. Caudal rami with hairy inner margins; 3rd

and 4th

caudal setae (counted from outer

side) of right ramus not parallel but crossing each other (Pl. 26c). P5 (Pl. 26e): coxal spine large,

conical, but relatively small on right P5; sensory seta of basis extending beyond the middle of

first exopodal segment; both margins of end claw with strongly developed denticles on inner and

outer margins (Pl. 26e); third exopodal segment distinct with 2 unequal spines. Endopod

unsegmented and slightly shorter than first exopodal segment.

Male

Metasomal wings asymmetrical; left wing more or less triangular with 2 unequal hyaline

spines; right wing larger than left wing with 2 unequal spines, outer spine being longer than inner

one and arising on small lobe-like structure. Second and third urosomites fringed with hairs on

ventral margin. Caudal rami strongly asymmetrical; right ramus being larger than left ramus and

armed at ventro-distal corner with massive tooth-like chitinous process, reaching almost half

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the length of ramus (Pl. 26f). Right antennule with spine on each of segments 8 and 10-15;

spines on segments 8 and 12 unequal in size; spinous process on antepenualtimate segment

generally straight with outcurved tip and slightly longer than next segment (Pl. 26 h, i). P5 (Pl.

26h-j): intercoxal hyaline lamella large and wedge-shaped; inner margin of basis with spherical

hyaline lobe; lateral spine of second exopodal segment lying slightly below the middle of outer

margin; end claw sickle-shaped, subproximal part enlarged on outer side as illustrated (Pl. 26h,

i). Endopod bottle-shaped and slightly shorter than second exopodal segment. Left P5: basis with

small hyaline lobe on inner margin.

Remarks

The relative length of spines on genital double-somite and the number of denticles on the

lateral margins of end claws of female P5 are variable. On grasping antennule, the spines on

segments 14 and 15 are variable in size, and so also the form of the spinous process on the

antepenultimate segment varies. The subproximal enlargement of end claw also varies to some

extent.

Ecology

N. intermedius has been found in moderately transparent or turbid permanent or

temporary water bodies of either slightly elevated places or plains (water temperature 26 -30ºC;

pH 7-8.5 and Secchi transparency 26-60 cm). It co-occurred with either A. mirabilipes or R.

indicus.

Distribution

It is noteworthy that during this study N. intermedius was presently found in only in few

localities. However, it was said to be quite common in various water bodies of Acharya

Nagarjuna University campus and around during late 1980s (Ranga Reddy, pers.commun). This

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shows that there is a shift in the distribution of this species. On the whole N. intermedius has a

rather restricted distribution in the Indian subcontinent. This is the sole neodiaptomd in Kerala.

Flößner, (1984) reported it from a medium-sized reservoir which is situated in the adjacent

lowland of the Nilgiri Hills, Tamilnadu, South India, at an altitude of 430 m.

Present records

Cumbum in A.P.; Irinjalakuda, Palakkad: Thrissur, Koyalamannam, Kundyangulam,

Shornur and Velacherry in Kerala State.


Neodiaptomus meggitti Kiefer, 1932

(Figs 69, 70)

Type locality: “Pools in Agri-Horticultural Gardens‖, Rangoon, Myanmar.


Female

Fourth and fifth pedigers completely fused together. Fifth pediger carrying delicate spine

or sensillum on either side of major articulation point. Spines on both wings almost equal in size.

Urosome of 2 somites. Genital double-somite only slightly longer than succeeding somite and

caudal rami combined, strong and asymmetrical. Caudal rami parallel, about as long as wide.

Caudal setae stout and curved; innermost seta with small bulge at base on outer side; the next

two 2 fused at base. P5: coxal spine massive, conical, pointed, but relatively small on right P5.

Basis with short, blunt prominent protuberance at about midlength of inner margin. Lateral spine

on second exopodal segment rather small, and lying over caudal surface of third exopodal

segment. Terminal claw incurved and with denticulate lateral margins. Endopod sturdy,

unisegmented with transverse row of close-set spinules subapically.

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Male

Fourth and fifth pedigers separated by distinct septum. Lateral wings of fifth pediger

small and asymmetrical; right wing relatively short, somewhat rounded, and with 1 apical and 1

lateral spine, both of equal size. Urosome bent to right side. Second and third urosomites fringed

with ventral hairs; third urosomite with very minute denticles clustered around dorso-distal

corner. Fourth urosomite produced at right distal corner into triangular lobe; better part of

dorsum covered with denticles. Right caudal ramus with small chitinous tooth on ventral distal

corner. Right antennule with spines in decreasing order as follows: 13>11>10>15>12=8.

Spinous process on antepenultimate segment nearly straight, sturdy, apex produced in to a short

pointed beak. Right P5: coxa somewhat squarish, produced at distal inner corner into short,

conical, upright, blunt hyaline plate, barely reaching midlength of left P5 coxa; intercoxal plate

as in Fig. 69 i. Coxal spine small, setiform and mounted on massive lobe. Basis stout, dilating

distally with somewhat large, crescentic hyaline lobe on proximal inner margin. First exopodal

segment about twice as wide as long and produced into sturdy acute spinous process at distal

outer corner. Second exopodal segment somewhat obovate. Lateral spine strong, straight and as

long its segment and inserted just anterior to midlength of outer margin. Terminal claw sturdy,

nearly as long as remaining appendage, proximal third thickened and produced into somewhat

rounded triangular bulge at distal outer angle. Endopod unisegmented, apex obliquely truncate,

ending in acute point and with row of spinules flanked by minute subapical spine. Left P5: coxa

with denticulate thumb-like lobe at outer distal corner. Basis wider than long, inner margin

somewhat convex, with crescentic hyaline lobe at about midlength. First exopodal segment

slender, over twice as long as wide, with hairy lobe at distal inner corner. Second segment small,

obovate, outer margin straight, inner margin inflated and fringed with long, coarse, densely

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arranged hair-like setae. Endopod cylindrical, overreaching midlength of second exopodal

segment, divided into 2 unequal segments by a faint suture.

Distribution

Outside its type locality in Myanmar, it was recorded only once, and, that too as strays at

Malacca in Malaysia. It was not found in the numerous samples collected from the main land of

India.

Ranga Reddy (2000) reported with detailed redescription the occurrence of N. meggitti

from the South Andaman Islands, which have similar geological history as Myanmar. On the

mainland of India, N. meggitti seems to have been replaced by its ecological equivalent, N.

intermedius Flössner, 1984. Both these congeners are confined to stagnant waters such as pools,

ponds, reservoirs, etc., and are generally rare in their occurrence. On the whole, N. meggitti is a

typical Oriental element.

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Genus Phyllodiaptomus Kiefer, 1936

Phyllodiaptomus: Kiefer, 1936c: 323; Kiefer, 1978: 159; Shen & Song, 1979: 148; Lai &

Fernando, 1981: 165; Dussart & Defaye, 1983: 92; 2001: 90, 175; 2002: 114-116 Ranga Reddy

& Venkateswarlu, 1989: 142; Borutzky et al., 1991: 413; Dumont & Ranga Reddy, 1993: 65-93;

Ranga Reddy, 1994:70-85; Dussart & Defaye, 2002: 114.

Generic diagnosis

Animals of moderate body size (0.8-1.33 mm). Female: lateral wings of fifth pediger

moderately developed, left wing frequently longer than right wing; urosome of 3 somites, genital

double-somite longer than the rest of urosomites including caudal rami; antennule extending to

end of caudal setae, or slightly longer caudal setae. P5: interccoxal spine short and strong.

Endopod long, mostly 2-segmented, with a row fine spinules on rounded apex; end claw with

hairy or spinulose margins; third exopodal segment small but distinct. Male: Right antennule

with spine on each of segments 8, 10-16 and short comb-like serrate process on antepenultimate

segment. Right caudal ramus generally without chitinous tooth on ventral side; on P5, intercoxal

plated distinct; second exopodal segment of right P5 thin, hollowing out on posterior surface and

generally with 1 short, bent, digitiform, lateral spinous process, mostly distal in position. Second

exopodal segment of left P5 with thumb-like apical process, and with or without hyaline fan.

The genus Phyllodiaptomus has been divided into two subgenera: Phyllodiaptomus s. s. and

Ctenodiaptomus Dumont & Ranga Reddy& Sanoamuang, 1996.

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Diagnosis of subgenus Phyllodiaptomus s. s.

Combshaped fan on made left P5 is transformed into a field of spinules; apical process of

the same leg large; male right P5 endopod spade-like. Female P5 endopod half or less than half

as long as first exopodal segment.

Type species: *Phyllodiaptomus blanci (Gurney & Richard, 1896)


Phyllodiaptomus (P.) tunguidus Shen & Tai, 1964

Phyllodiaptomus (P.) longipes Kiefer, 1965

Phyllodiaptomus (P.) christinae Dumont, Ranga Reddy & Sanoamuang, 1996

Phyllodiaptomus (P.) surinensis Sanoamuang & Yindee, 2001

Phyllodiaptomu (P.) thailandicus Sanoamuang & Teeramaethee, 2006

Phyllodiaptomus (P.) irakiensis Khalaf, 2008

Diagnosis of subgenus Ctenodiaptomus

Comb-shaped fan on male left P5 prominent; apical process of the same leg small; male right P5

endopod pyriform. Female P5 endopods more than half the length of first exopodal segment.

Type species: *Phyllodiaptomus (C.) annae (Apstein, 1907)

Other valid species: *Phyllodiaptomus (C.) sasikumari Ranga Reddy & Venkateswarlu, 1989

*Phyllodiaptomus (C.) wellkensae Dumont & Ranga Reddy, 1993

Phyllodiaptomu (C.) praedictus Dumont & Ranga Reddy, 1994

Of the species listed above, the asterisked ones are known from India.

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Keys to the females of Indian Phyllodiaptomus spp.

1. Left proximal region of genital double-somite distinctly dilated and armed with and

extraordinarily large, somewhat curved, laterally-directed spine………………P. wellekensae

Left proximal region of genital double-somite undilated and armed with normal, laterally or

posterolaterally-directed spine………………..……………………………………………….2

2. Inner spine on third exopod segment of P5 setiform and extending beyond tip of end

claw…………………………………………………………….……………………..P. annae

Inner spine on third exopod segment of P5 normal and never reaching tip of end claw…..…3

3. Left wing long and posteriorly directed; genital double-somite with slight bulge just below the

spine; genital spines postero-laterally directe……….…………………………………P. blanci

Left wing short and posterolaterally directed; genital double-somite without any bulge on right

margin; both genital spines laterally-directed …………….………………………P. sasikumari

Key to the males of Indian Phyllodiaptomus spp.

1. On left P5, second exopod segment without apically-serrate hyaline structure between apical

thumb-like process and inner seta; on right P5, tip of coxal hyaline plate produced; second

exopod segment with ledge at about midlength of inner margin, and hyaline lobe at distal outer

corner ………………………………………………….……………………………….P. blanci

On left P5, second exopod segment with apically serrate hyaline structure between apical

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thumb-like process and inner seta; on right P5, tip of coxal hyaline lobe not produced; second

exopod segment without ledge on inner margin, and with or without hyaline lamella or

spinous projection………………………………………………………………………………2

2. on right P5, second exopod segment rectangular and with short, hyaline, spinous projection

between lateral spine and end claw; first exopod segment short and blunt at distal outer corner;

basis with long, wavy hyaline lamella……………….…………………………..P. wellekensae

On right P5, second exopod segment somewhat oval and without spinous projection between

lateral spine and end claw; first exopod-seegment with spinous process at distal outer corner;

basis with 2 hyaline lobes on inner margin…………………………………………………….3

3. On right P5, coxal hyaline plate short, roughly triangular; second exopodal segment

characteristic in shape as illustrated; basis stount……………………………………...P. annae

On right P5, coxal hyaline plate long, conical; second exopodal segment elongately oval; basis

slender……………………………………………………………………………...P. sasikumari

Phyllodiaptomus blanci (Guerne & Richard, 1896)

(Figs 71-73, Pls. 27, 28)

Diaptomus blanci: Guerne & Richard, 1896: 53-56, Figs 1-5; Meissner, 1904: 649; Gurney,

1907: 23, Fig. 29; Tollinger, 1911: 112, Fig. F; Rylov, 1930: 193, Figs 63, 1-5; Rylov 1936: 149.

Phyllodiaptomus blanci: Kiefer 1936c: 321-323, Figs 1-5; Brehm, 1953: 276-279, Figs 41-42;

Dumont & Van de Velde, 1977: 62, Figs 10 A-D; Kiefer, 1978; 159, PI. 71; Ranga Reddy &

Devi, 1990b: 168-170, Figs 57, 68, 71: Venkateswarlu, 1989: 12-20, Figs 1-56; Ranga Reddy &

109

Venkateswarlu, 1989: 142; Borutzky et al., 1991. 414-416, Fig. 184; Dumont & Ranga Reddy,

1993: 86, Figs 119-132; Ranga Reddy, 1994: Figs 376-406; Dussart & Defaye, 2001: 176. Fig.

37; 2002: 114; Ambedkar, 2005: 51-55, Figs 1-14.

Phyllodiaptomus peregrinator: Brehm, 1950: 2-4, Figs 1a-h.

Phyllodiaptomus subquadratus: Borutzky et al., 1991: 416, Fig. 185.

Phyllodiaptomus irakiensis: Khalaf, 2008: 257-269, Figs 1-5, Pl.1.

Type locality: Shallow water bodies in the vicinity of Bukhara, Uzbekistan Republic.



Female (Fig. 71, Pl. 27)

Fourth and fifth pedigers fused. Metasomal wings asymmetrical; left wing generally

narrow, digitiform, posteriorly directed, and armed with a spine on the tip. Right wing bilobed.

Wings varying as in Fig. 71c-k. Urosome of 3 somites; genital double-somite longer than

succeeding 2 somites and caudal rami, asymmetrical and right side being more irregular than

left side, right lateral margin consistently dilated just below the right spine; spines unequal and

variable in size. Second urosomite smallest proximal part telescoped into genital double-somite.

Anal somite distinctly forked behind. Position, shape and orientation of lateral wings as well as

spines on genital double-somite are varying within and between populations (Fig. 71 c-k, Pl.

27a, c). Caudal rami parllel, symmetrical, and with fine hairs along both margins. P5:

symmetrical, coxal spines of both legs relatively small. Basis with elongate seta, extending

beyond the first exopodal segment. First exopodal segment twice as long as wide. Second

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exopodal segment (end claw) armed with close-set hairs lateral margins. Third exopodal

segment small but distinct with 2 unequal spines. Endopod vaguely divided into 2 segments,

sturdy and slightly shorter than first exopodal segment.

Male (Fig. 72, Pl. 28)

Genital somite with a short spine at right posterior corner and indented at left posterior

corner. Caudal rami with hairy inner margin. Right antennule: spine on each of segments 8 and

10-16. Spine on segment 13 longest, spine on segment 16 shortest. Relative length of spines in

decreasing order as follows: 13>11>10>8>14>15>12>16; antepenultimate segment having

short, comb-like process with 3-9 teeth. Right P5: coxa with large, roughly triangular hyaline

plate at distal inner corner; basis with hyaline lobe on inner proximal margin; first exopodal

segment shorter than wide, with posterior outer corner expanded into a pointed lobe; second

exopodal segment much flattened, generally twisted around its axis and with a ledge on inner

margin and hyaline outgrowth on outer margin between lateral spine and end claw; lateral spine

digitiform, distal in position and generally outcurved. End claw slightly curved, stouter at base.

Endopod sturdy and variable in shape. Left P5: coxa roughly rectangular and with small spine at

distal inner corner: Basis with narrow hyaline lobe on distal inner margin (see below). Proximal

exopodal segment large and with hairy lobe on inner margin: distal segment produced in to

thumb-like process apically and carrying jointed seta on inner margin. Endopod unisegmented,

nearly as long as proximal segment of the exopod.

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Remarks

This study brings out the morphological variation, within certain limits, of the following

features, which are otherwise quite diagnostic of P. blanci: in female, the shape of the

posterolateral wings as well as the spines on the first urosomite; in male right P5, the shape of

intercoxal plate, and the size of hyaline lobe on basis as well as second exopodal segment.rarely,

the hyaline lobe on the basis of the male left P5 is produced into a short digitiform process.

It is pertinent here to assess the validity of Iraqui Phyllodiaptomus irakiensis Khalaf,

2008. A close look at the description and figures of this species shows it is not distinct from the

most widespread and morphologically variable P. blanci. This is evident from the following

points:

(1) The left metasomal wing of the female is always produced and simple in

P.blanci. However, Khalaf (2008) mistook the transverse fold of the wing, an

artifact, for a separate lobe in P. irakiensis.

(2) The occurrence of conspicuous hyaline lobe on the dorsal side of second and

third urosomites of improbable in diaptomids.

(3) Both margins of caudal rami are having hairy in P. irakiensis as well.

Obviously, Khalaf has overlooked the important works of Dumont & Ranga

Reddy (1993), Ranga Reddy (1994) on P. blanci.

(4) The spines on each caudal ramus in both sexes are only imaginary.

(5) In female P5, the endopod always has a vague cross septum in P. blanci and

P. irakiensis.

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Similarly, the other characters proposed by Khalaf as important in distinguishing P.

irakiensis from P. blanci are indeed variable. What is perplexing is that Khalaf depicts the

endopods of female P5 (Khalaf, 2008, Fig. 4 G, I) as very short, but takes no congisance of the

same while comparing the two species. In all probability, P. irakiensis is synonymous with P.

blanci.

Distribution

Previous records

Iran, Aral Sea, Iraq, India and Nepal. Though not common, this species is widely

distributed in India, especially in temporary waters.

In the present study P. blanci was noticed in various localities of Karnataka and

Andhra Pradesh, Orissa and Chattisgarh States of peninsular India. In Tamilnadu, this

species is replaced by either P. annae or P. wellekensae.

Ecology

P. blanci inhabits permanent, semi-permanent and temporary habitats in which the

water temperature range was 19-33ºC, pH 6.5-8 and Secchi transparency 15-40 cm. According to

the existing literature, this species is not only eurytopic but also euryhaline (Kiefer, 1978).

According to Sewell (1934), it is a true freshwater species and its presence in such brackish

habitats as Chilka Lake during the rainy season is only accidental. It possesses only a weak

adaptability to the increased chloride content. Its life cycle was studied by Kiselev (1930) in one

of the ponds around Bukhara. In large lakes, it is concentrated in the surface layer (0-2 M) of the

pelagic zone. P. blanci is amenable to cultivation under laboratory conditions. According to

Ranga Reddy & Devi (1990b) who raised this speicies from its eggs, it completes the naupliar

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phase in 6 days and copepodid phase in 9 days at a room temperature of 26ºC-29ºC. In the

present study it co-occurred on different occasions with H. viduus, H. cinctus, S. indicus, M.

pseudohebes or N. schmackeri.

Conservation status: LR

Phyllodiaptomus wellkensae Dumont & Ranga Reddy, 1993

(Figs 74-76, Pl. 29, 30)

Phyllodiaptomus wellekensae: Dumont & Ranga Reddy, 1993: 66-80, Figs 1-68; Ranga Reddy,

1994: 406 Figs a-z.

Type locality

A small, man-made, temple pond, opposite the entrance road to Vivekanandapuram in

Kanyakumari, South India.

Body size. Female 1.14-1.36 mm; male 1.19- 1.27 mm.


Lateral wings of fifth pediger moderately developed and asymmetrical; left wing narrow,

somewhat triangular, more extensive than right wing and posterolaterally directed; right wing

wider than left wing and bilobed. Genital double-somite asymmetrical right side almost smooth

except at the middle where it slightly bulges; left side distinctly dilated below left wing and

armed with large, outcurved, laterally-directed spine, below which the lateral margin of the

somite quite smooth; right genital spine unusually smaller than left one, almost straight and lying

on dorso-lateral margin opposite to left spine. Caudal rami parallel, symmetrical, about 1.5 times

as long as wide with hairy outer and inner margins. Antennules extending beyond the tips of

caudal setae by last 2 segments. P 5: Coxal spine large, conical, pointed and arising from lobe-

like structure; sensory seta on basis long, extending beyond third exopodal segment; proximal

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lateral spine on second exopodal segment as long as outer spine on third exopodal segment; both

spines with smooth lateral margins; end claw generally outcurved or, sometimes, straight with

about 4-9 spinules on outer margin and 12-15 on inner margin; third exopodal segment almost

squarish, well-defined at base; its inner setiform spine slightly dilated at base, with serrate lateral

margins and extending to about 2/3 length of end claw. Endopd strong, 2-segmented, about 0.7

as long as inner margin of first exopodal segment; apex rounded with transverse row close-set

spinules and slightly larger spine on each side.

Male

Lateral wings of fifth pediger small, postero-laterally directed; each wing with 1 small

apical spine and 1 inner sensillum; spine on right wing relatively large and placed on small

papilla. Genital somite with short, slender spine at right distal corner. Second and third

urosomites fringed with hairs on ventral margin. Caudal rami symmetrical, 1.6 times as long as

wide; lateral seta only slightly stouter than other setae.with spine on each of segments 8 and 10-

15; relative lengths of spines in decreasing order as follows; 13>11>10>14>15>8>12;

antepenultimate segment produced into short, comb-like serrate process with about 2-6 teeth. P5

: Coxa produced at distal inner corner into short, dilated, roughly triangular hyaline plate, always

pointing towards and arching over proximal inner region of basis of left leg; distal border of this

plate convex whereas its inner margin straight. Coxa also armed with strong, almost straight

spine, arising from lobe-like structure at mid-distal border of caudal surface. Basis almost

rectangular, 1.3 times as long as median width, distal inner region slightly dialted in lateral view;

inner margin wth long, wavy hyaline lamella; basis also with longitudinal chitinous ridge at the

middle of proximal half on posterior surface. First exopodal segment about 1.7 times wider than

long, with short, blunt outer corner. Second segment nearly rectangular, thin, hollowing out on

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posterior surface and with short, pointed or rarely blunt, hyaline spinous projection at distal outer

corner between lateral spine and base of end claw; lateral spine digitiform, generally incurved,

closely adpressed to distal outer margin and extending beyond posterior border of the segment.

End claw 1.5 times as long as exopod, slightly curved, almost sickle-shaped, with blunt tip.

Endopod large, pyriform and reaching the proximal third of inner margin of second exopodal

segment. Left P5 reaching posterior border of first exopodal segment of right leg5. Basis with

small triangular hyaline lamella, folding over distal inner margin. Second exopodal segment

produced in to thumb-like apical process, lined with finely serrate hyaline lamella on inner

margin; inner seta large, modified, proximal third or so, dilated, jointed and studded with

numerous fine spinules; flanked by apical thumb-like process and inner seta is cock‘s comb-like,

apically dialted and serrate hyaline structure. Endopod short, 2-segmented, with obliquely

truncate apex.

Remarks

P. wellkensae belongs to the blanci -group, which consists of three species, viz. P.

blanci, P. annae and P. sasikumari (Ranga Reddy & Venkateswarlu, 1989). Within this group,

this species closely resembles P. blanci, but can be separated easily, inter alia, by considering

the following characters: in female, the left wings of fifth pediger and the genital double-somite

and its spiness; in male, the shape of coxal plate, basis and its inner hyaline lamella, second

exopodal segment and its spinous hyaline projection between lateral spine and end claw of right

P5, and the presence of a large cock‘s comb-like, serrate hyaline structure on the second

exopodal segment of left P5. The last mentioned charcter is shared only by two other

Phyllodiaptomus spp., viz. P. annae and P. sasikumari, from which this species can be readily

distinguished by the absence of spinous process at the distal outer corner of first exopodal

116

segment, by the characteristic shape of coxal plate and second exopodal segment of male right

P5, and also by the form of genital double-somite and its dissimilar spines in female.

Distribution and ecology

It appears to be endemic to the South Indian State of Tamilnadu. It probably prefers

shallow, seasonal or permanent water bodies such as ponds and pools.

Conservation Status: VU B2.

Phyllodiaptomus annae (Apstein, 1907)

(Figs 77-79, Pls. 31, 32)

Diaptomus annae: Apstein, 1907: 221-224, Fig. Q; Tollinger, 1911: 44, Fig. F.

Phyllodiaptomus annae: Kiefer, 1936c: 321-323, Figs 6-10; Brehm, 1953: 279-282; Rajendran,

1973: 120, Figs 5a-j; Fernando, 1974: 60, Figs 239-243; Lai & Fernando, 1981: 165-168, Figs

36-44; Dussart & Fernando, 1985: 238-239, Figs 40-47; Venkateswarlu, 1989: 29-37, Figs 1-48:

Ranga Reddy & Venkateswarlu, 1989: 142; Dumont & Ranga Reddy, 1993: 86-87, Figs 133-

145 ; Ranga Reddy, 1994 : Figs 407-343.

Type Locality: Colombo Lake, Sri Lanka.




Rostral spines moderately developed and acute. Lateral wings of fifth pediger

asymmetrical, left wing narrow, roughly triangular and laterally directed; right wing wide and

bilobed. Genital double-somite slightly asymmetrical, longer than rest of urosome including

caudal rami; genital spines small, triangular and laterally directed. Lateral wings of fifth pediger

117

and genital doubl-somite varying as in Fig. 77g-l, Pl. 31a, b. Caudal rami 1.5 times as long as

wide. P5: coxal spines of both legs small, equal and pointed. Sensory seta of basis shorter than

first exopodal segment. Third exopodal segment with 2 unequal spines, inner spine long

setiform, extending beyond end claw. Endopod strong, 2-segmented, slightly shorter than first

exopodal segment.

Male (Fig. 78, Pl. 32)

Rostral spines as in female. Caudal rami symmetrical, 1.6 times as long as wide; lateral

caudal seta stoutest. Right antennule with spine on each of segments 8 and 10-16;

antepenultimate segment produced into short, comb-like structure with 2-8 teeth. Right P5: coxa

produced at distal inner corner into short, broadly triangular, apically-blunt, hyaline plate. Basis

longer than broad, with 2 hyaline lobes on inner margin. First exopodal segment produced at

distal outer corner into moderately large, pointed, spinous process. Second segment bent

outwards and characteristically dilated in the distal half of outer margin; lateral spine digitiform

and pressed large, more than half as long as second exopodal segment. Left P5: coxal spine very

small. Second exopodal segment with apically-serrate, membranous hyaline structure between

apical digitiform process and modified seta.

Remarks

The present study brings out the observed range of inter-population variation in the

metasomal wings and genital double-somite and its spines in female, the coxal plate and endopod

of right P5 and the antepenultimate process in the grasping antennule in male. Seta on the basis

of leg t in female is invariably shorter than the first exopodal segment, but the same is longer in

P. blanci. The inner spine on the third exopod segment is extending beyond the tip of end claw.

118

By contrast the seta is shorter in all other Phyllodiaptomus spp. All important morphological

differences among the six Phyllodiaptomus spp. are summarized in Table 21.

Distribution

South India (Brehm, 1953, Rajendran, 1973) and others. Srilanka, Thai Land.

Surprisingly, this species has not yet been known from any other State than Tamilnadu in India.

What was reported from Thailand as P. annae by Lai & Fernando (1981) and Boonsom (1984) is

synonymous with P. praedictus (see Dumont & Ranga Reddy, 1994).

Ecology

P. annae is found in temporary shallow, large permanent ponds, and village tanks in

which the water temperature ranged from 25-30ºC and pH 6.5-7.0 with Secchi transparency 10-

137cm. Overall, P. annae is rare as compared to P. blanci. According to Fernando (1980), it is

eurytopic in Sri Lanka. Lai & Fernando (1981) also recorded it in diverse habitats such as

reservoirs, fish ponds and rice fields. Boonsom (1984) reported it from a river. It was often

observed to co-occur with Spicodiaptomus chelospinus, P. greeni (Venkateswarlu, 1989),

Heliodiaptomus viduus, or Rhinediaptomus indicus.

Conservation status: VU B1.

Phyllodiaptomus sasikumari Ranga Reddy & Venkateswarlu, 1989

(Figs 80, 81, Pl. 33)

Phyllodiaptomus sasikumari: Ranga Reddy & Venkateswarlu, 1989: 133-142, Figs 1-49.

Dumont & Ranga Reddy, 1993: 91; Ranga Reddy, 1994: Figs 435-448; Dussart & Defaye,

2002: 115.

119

Type locality: Temporary pond at a hamlet called Kawalapara, 5km from Shornur town in the

Palghat district, South India.



Female

Fourth and fifth pedigers fused, fusion being indicated by indentation on each side. Fifth

pediger with moderately-developed, symmetrical wings; left wing narrow, more or less

triangular and posterolaterally directed; right wing bilobed with outer part being better

developed; each wing with 2 unequal spines, apical spine being larger than subapical spine;

apical spine of left wing generally directed laterally. Urosome of 3 somites; genital double-

somite longer than succeeding 2 somites plus caudal rami, roughly symmetrical with

subproximal region dilated and lying 2 spines opposite to each other. Anal somite distinctly

forked behind. Caudal rami almost parallel, symmetrical, 1.5 times as long as wide, with fine

hairs along both margins; setae normal except for innermost seta of each ramus showing slight

bulge at base on outer side (Fig. 55 a). P5: right leg slightly stouter than left leg. Coxa with

relatively large, conical, posterolaterally-directed, blunt spine; basis much smaller than coxa;

lateral sensory seta extending beyond first exopodal segment; second exopod segment tapering

into a claw, both margins lined with close-set delicate spinules on nearly straight lateral margins,

as illustrated and with short outer spine near base of third segment; third exopod segment small

but well defined, with 2 unequal spines. Endopod divided into 2 segments; apex rounded with

transverse row of close-set spinules and small spine on each side.

Male

120

Urosome of 5 somites, attenuating but little behind and bent to rightside. Genital somite

with a fine sensillum at distal outer corner. Second urosomite fringed with ventral hairs. Anal

somite slightly forked. Caudal rami symmetrical with hairy inner margins. Right antennule with

spine on each of segments 8 and 10-16. Relative length of spines in decreasing order as follows:

13>11>10>8>15>14>12>16. Antepenultimate segment produced into short, comb-like process

with 3-5 teeth. P5: Coxa with a large, conical, hyaline plate lying over inner margin of basis of

left leg; basis nearly twice as long as median width and lined with 2 hyaline lobes on inner

margin; first exopodal segment with large, spinous process, reaching nearly the mid-outer margin

of second exopodal segment ; second segment elongately oval in outline; lateral spine digitiform

and adpressed to distal outer margin of the segment and extending beyond its posterior border;

first and second exopodal segments, especially the second one, frequently twisted around their

axis and bent inward; end claw smoothly curved and gradually attenuating into acuminate point.

Endopod relatively large, 0.5 as long as second exopodal segment, inner margin almost straight

or concave with 0-2 dentate projections subterminally. Left P5: coxal spine small; second exopod

segment with apically-serrate, membranous hyaline process, flanked by apical spinous process

and modified seta. Endopod bottle-shaped.

Ecology and Biogeography

Present survey indicates P. sasikumari prefers shallow, turbid, temporary waters such as

seasonal ponds and pools in which temperature range was 25-30ºC and pH 7.0-8.0 with Secchi

transparency 5-45 cm. In the present study, in all the samples collected from various habitats of

Kerala, it was often the sole calanoid, numerically dominating all other crustacean zooplankters.

On contrary, it was poorly represented in clear water pools and puddles in paddy fields (Ranga

Reddy & Venkateswarlu, 1989). It is endemic to Kerala State. For distribution, see Fig. 81.


121

Genus Sinodiaptomus Kiefer, 1932

Sinodiaptomus; Kiefer, 1932a: 475; Kiefer, 1936a: 229; Kiefer, 1978: 157; Brehm, 1950: 17;

Shen & Song, 1979: 119; Dussart & Defaye, 1983: 100; 2002: 124; Borutzky et al., 1991: 418;

Ranga Reddy, 1994: 195-208.

Generic diagnosis:

Female. Endopod on P5 without apical setae, middle endopod segment on P2 without

Schmeli‘s organ. Male right antennule with comb on antepenultimate segment. Right P5: basis

with large chitinous projection on distal posterior surface, overlapping the first exopodal

segment. Endopod small. Left P5: entire posterior surface or its inner side of terminal thumb on

exopod with transverse, membranous folds, superimposing one another.

Kiefer (1936) divided the above genus into two subgenera, viz. Sinodiaptomus s. str. and

Rhinediaptomus.

1.Subgenus Sinodiaptomus s. str. Kiefer, 1932

Animals somewhat large (1.6-2.5 mm). Female fourth pediger with middrosal process. Male

right P5: Basis without chitinous process at proximal inner corner. Second exopodal segment

short, wide and concave on posterior surface; lateral spine small and distal.

Type species : Sinodiaptomus (sinodiaptomus) chaffanjoni (Richard, 1897)


Sinodiaptomus (Sinodiaptomus) sarsi sarsi (Rylov, 1923)

Sinodiaptomus (Sinodiaptomus) sarsi valkanovi Kiefer, 1938

122

1.Subgenus Rhinediaptomus Kiefer, 1936

Animals moderate size (1.12-1.46 mm). Female fourth pediger without middorsal

process. Male right P5: Basis with chitinous process at proximal inner corner. Second exopodal

segment long slender and concave on the posterior surface; lateral spine proximal in position.

Type species: Sinodiaptomus (Rhinediaptomus) indicus Kiefer, 1936


Sinodiaptomus (Rhinediaptomus) mahanandiensis Ranga Reddy & Radhakrishna, 1980

Both species of Rhinediaptomus were encountered in the present survey.

Key to the females of Sinodiaptomus (Rhinediaptomus) spp.

1. On P5, endopod shorter than first exopodal segment …………………………….S. (R.) indicus

The same as long as first exopod segment ……………………..……….S. (R.) mahanandiensis

Key to the males of Sinodiaptomus (Rhinediaptomus) spp.

1. On right P5, lateral spine on second exopod segment distinctly proximal and having a strong,

trapezoidal, chitinous structure at its base; on left P5, terminal thumb of exopod with

membranous folds extending from outer to inner margin ………………….……….S. (R.) indicus

On right P5, lateral spine arising from about the middle of second exopod segment and without

chitinous structure at its base; on left P5, terminal thumb of exopod having membranous folds on

inner side alone……………………………………………………...……..S. (R.) mahanandiensis

Sinodiaptomus (Rhinediaptomus) indicus Kiefer, 1936

(Figs 82, Pl. 34)

Sinodiaptomus (?) indicus, Kiefer1936a: 226-229, Figs 1-5.

Rhinediaptomus indicus: Brehm, 1953: 283-286, Figs 45-48; Brehm, 1954: 417; Brehm, 1963:

163, 165, Figs 20-25; Singh, 1972: 209-215; Rajendran, 1973: 117.

Figs 4a-k; Reddy, 1977: 79, PI. 12, Figs 1-8.

123

Sinodiaptomus (Rhinediaptomus) indicus: Dussart & Defaye, 1983: 100; 2002: 125; Borutzky et

al., 1991: 423- 424, Fig. 188; Ranga Reddy, 1994: Figs 1092-1102; Ambedkar, 2005: 1-10.

Type locality: ―Tumbha Kanta Seru‖ at Rajahmundry in Andhra Pradesh State (erstwhile

Madras Presidency), South India.


Body Size. 1.5-1.8 mm; male 1.3-1.7 mm.

Female (Figs. 82a-d, Pl. 34a-d)

Rostral spines small. Fourth and fifth pedigers fused to each other. Lateral wings of fifth

pedigers small and asymmetrical; left wing somewhat larger and more extensive than right wing,

each wing with strong hyaline spines. Genital double-somite distinctly longer than the rest of the

urosome, including caudal rami; lateral margins uneven; mid-lateral region of right side dilated.

Caudal rami 1.3 times as long as wide, outer and inner margins hairy.

Male (Figs. 82e-l, Pl. 34e-h)

Fourth and fifth pedigers fused except at lateral margins. Right wing of fifth pediger

slightly narrower than left wing and carrying stronger apical spine with tubercle. Urosome 5-

segmented and bent towards right side; genital spine small, slender. Caudal rami as illustrated in

Fig. 81e. Right antennule with spine on segments 8 and 10-16; length of spines in decreasing

order as follows; 13>11>15>10>14>8>16>12; spine on segment 11 strong, bent backwards:

comb on antepenultimate segment with 6-8 teeth. Right P5. Coxa with large, crescentic

chitinous outgrowth at distal inner corner and strong hyaline spine mounted on lobe at mid-distal

region; basis wider than long, with massive chitinous outgrowth, ending in 2 unequal, spinous

process at proximal inner corner, 1 small, hyaline lobe at mid-inner margin, and 1 subproximal

and 1 distal chitinous projection near inner margin, on posterior surface; second exopod segment

2-3 times as long as wide, with minute chitinous knob; end claw strong, slightly variable in

124

shape. Endopod unsegmented. Left P5: Basis with small hyaline lobe on distal inner margin;

Terminal thumb on exopod with transverse, membranous folds (Pl. 32h, superimposing one

another. Endopod 2-segmented, reaching distal margin of first exopodal segment.

Distribution

R. indicus is a widely distributed and most common species in South India.

Ecology

Inhabits seasonal ponds, pools during the monsoon activity (June-November) in which

the was 24-31ºC, pH 6.5-8.0, Secchi transparency 15-58 cm. According to Singh (1972), it

appears to feed round the clock, but intensely at night; the females feed more than the males and

stage V copepodids. S. (R.) indicus co-exists with P. greeni, P. blanci and H. viduus.

Conservation status: Lower Risk (LR): Least Concern (lc).

Sinodiaptomus (Rhinediaptomus) mahanandiensis Ranga Reddy & Radhakrishna, 1989

(Fig. 83 Pl. 35)

Rhinediaptomus mahanandiensis: Ranga Reddy & RadhaKrishna, 1980: 194-198, Figs 1-10.

Sinodiaptomus (Rhinediaptomus) mahanandiensis: Dussart & Defaye, 1983: 100; 2002:125;

Ranga Reddy, 1994: Figs 1111-1120.

Type locality: A rain-pool at Mahanandi near Nandyal town in Andhra Pradesh State, South

India.

Body size. Female 1.87-1.72 mm; male 1.37- 1.90.

Female

Closely resembles S. (R). indicus but differs mainly in the following respects: a) body

slightly stouter, b) genital double-somite with almost straight left margin; median rightside bulge

125

less prominent; spines laterally directed, and c) P5: first exopodal segment only slightly longer

than wide; lateral margins of end claw generally straight; endopod as long as first exopodal

segment.

Male

Differs form S. (R.) indicus Kiefer in the following points: a) body somewhat stouter, b)

caudal rami 1.8 times as long as wide, c) right P5: lateral spine arising from about the middle of

the outer margin of second exopodal segment; no chitinous lobe at base of this spine, d) left P5:

terminal thumb having about 8 membranous folds on inner side.

Remarks

S. (R.) mahanandiensis is unique, inter alia, by the male right P5 having the lateral spine

at midlength of the second exopodal segment and without chitinous lobe at its base, and the

terminal thumb of left P5 with incomplete transverse striations. The larval morphology of this

species (Rao, 1990) vis-à-vis S. (R.) indicus and the allopatric distribution leave no doubt that it

is a distinct species.

Distribution

Not found any where outside Mahanandi, the type locality of the species, in South India.

Ecology

Occurs in small, seasonal, generally turbid water bodies, where it has replaced its

congener, S. (R.) indicus Kiefer. It appears soon after the monsoon showers refill these

ephemeral habitats around July, and lasts till about November. A dominant plankter in its type

locality, it co-occurs with Paradiaptomus greeni, a typical example of ephemeral waters, and

Neodiaptomus schmackeri.

Conservation status: Vulnerable (VU D2)

126

Genus Megadiaptomus Kiefer, 1936

Generic characters

Rather large animals, confined to certain temporary waters such as seasonal pools and

ponds in India and Sri Lanka. Body robust, long (2.5-3.0 mm). Female pediger 5 with poorly

developed, slightly asymmetrical wings. Genital double-somite and fifth pediger with tiny

sensory spines. Presence of lateally-spinulose papillae, instead of simple spines, on outer distal

margin of exopodal segments of P2-P4. Right male antennule with spiniform process on

segments 8 and 10 to 13; antepenultimate segment with digitiform process. Right male P5 with

long obtuse lobe situated on caudal side of basis. Exopod 2 with lateral spine inserted on frontal

surface in distal half. Left male P5 ending in large finger-like structure and strong spine.

Type species: Megadiaptomus hebes Kiefer 1936

Other valid species

Megadiaptomus pseudohebes Ranga Reddy, 1987

M. pseudohebes alone was encountered in the present study.

Key to the females of Megadiaptomus spp.

1. Genital double-somite twice as long as anal somite plus caudal rami; P5 coxa ornamented and

endopod shorter than first exopodal segment …………..............................................M. hebes

Genital double-somite only 1.4 times as long as anal somite plus caudal rami; P5 coxa

unornamented and endopod longer than first exopod………………. …………M. pseudohebes

127

Key to the males of Megadiaptomus spp.

1. Accessory spinous process on the posterior face of second exopod of right P5 distinctly

proximal; coxa on left P5 ornamented; coxa of left P5 ornamented……………………..M. hebes

Accessory spinous process on the posterior face of second exopod of right P5 present at

midlength; coxa of left P5 unornamented and end claw on right P5 as

illustrated……………………………………………………………………….…M. pseudohebes

Megadiaptomus pseudohebes Ranga Reddy, 1987

(Figs 85-87, Pl. 36)

Megadiaptomus pseudohebes: Ranga Reddy, 1987: 247-262, figs 1-59; Dussart & Defaye, 2002:

116; Ambedkar, 2005: 61-63: Figs 46-49, Figs 1-9.

Type locality: Rain-fed pond at Kondakarla village near Visakhapatnam.



Female (Fig. 85, Pl. 36a-d)

Rostral spines short and blunt. Fourth and fifth pedigers fused. Metasomal wings

generally triangular, and almost symmetrical; each wing with 2 small, unequal, hyaline spines.

Urosome bimerous, genital double-somite nearly twice as long as anal somite. Caudal rami

symmetrical, each ramus about 1.5 times as long as wide, with coarse hairs on inner margins.

P1-P4 (Pl. 36 b, c) outer-edge spines of exopodal segments of of P2-P4 alone modified in

to spinose papillae; otherwise typical of subfamily Diaptominae.

128

Fifth legs strongly built. Coxa roughly rectangular. Basis subquadrate, with short, sensory

lateral seta. First exopodal segment about 1.5 times as long as wide. Endopod unsegmented, but

indented on proximal inner margin, invariably longer than first exopodal segment. First exopodal

segment about 1.5 times as long as wide. Second segment (end claw) armed with close-set

delicate spinules on lateral margins. Other details as in Fig. 84f.

Male (Figs 86, 87, Pl. 36e)

Fourth and fifth pedigers completely fused as in female. Metasomal wings small and

symmetrical. Urosome of 5 somites. Right antennule with spine on each of segments 8 and 10-

13; spines on segments 11 and 13 generally slender and unequal in length; antepenultimate

segment spinous process elongate, stout, somewhat dilated apically and highly variable as in Fig.

86 h-r. P5 (Fig. 87, Pl. 36e): Right leg strongly built. Coxa roughly rectangular, distal inner part

somewhat expanding and arching over coxa of left leg on posterior face and armed with a slender

hyaline spine. Basis inner margin with triangular hyaline lobe halfway on inner margin. First

exopodal segment much wider than long, with irregular hyaline membrane over disto-inner

border, and 2 hyaline lobes of varying nature. Second exopod with a lateral spine at disto-outer

margin and same segment carrying large, roughly triangular, plate-like accessory process,

obliquely lying at about midlength of posterior face and varying in shape as in Fig. 87 c, d. End

claw somewhat broad and straight in the proximal half whereas distal part bending at 60-70

degrees to proximal part. Endopod as long as first exopodal segment and its apex armed with

thick row of short spinules. Left P5: Basis longer than broad, carrying knob-like hyaline lobe on

inner margin. Second exopodal segment with 1 plate-like process, serrate on inner margin as well

as apex, and 1 strong, curved spinous process with finely serrate inner margin. Endopod

unisegmented, apex lined with minute spinules.

129

Remarks

The spinous process on antepenulatimate segment shows wide inter- and intra-

population variation in length and shape. Similarly, on male right P5, position of disto-lateral

spine on second exopodal segment also varies between populations (Fig. 87c, d, Pl. 36e). It has

already been clarified by Ranga Reddy (1988) that Heliodiaptomus alikunhii Sehgal, 1960,

rightly belongs to the genus Megadiaptiomus based on, inter alia, the large body size and the

presence of the characteristic papillae on P2-P4. However, for want of the type specimens, a

question mark still hangs on the identity of H. alikunhii. Given the fact that the type localities of

M. pseudohebes and H. alikunhii are close to each other geographically, it is most probable that

species are synonymous to each other, in which case M. pseudohebes would sink into the

synonymy of H. alikunhii according to the Principle of Priority (ICZN Art.23.3.3).

Distribution

Distribution: The species was first reported as Megadiaptomus hebes from seasonal

ponds on the outskirts of Guntur town by Ranga Reddy & Devi (1985). Ranga Reddy (1988)

found M. pseudohebes (= M. hebes) in a rain-fed pond at Kondakarla near Anakapalli town.

Subsequently it was found in five successive years (2003-2007) in Vejendla quarry pools near

Guntur (see Conservation Status of Indian diaptomids).

Ecology

Found but rarely in temporary water bodies where the temperature was from 22.5-26 ºC,

pH 7.0-8.0 and transparency 28-45cm; often co-occurring with N. schmackeri and P. blanci and

H. viduus.

Conservation status: CR B2.

130

Megadiaptomus hebes Kiefer, 1936

(Figs 88)

Megadiaptomus hebes Kiefer, 1936: 77-79, figs 1-6; Brehm, 1950: 17 (indistribution list);

Brehm, 1953: 302(in key); Brehm, 1954: 413 (in distribution list); Dussart & Fernando, 1985:

239, figs 48-53; Dussart & Defaye, 2002: 116.

Zeylanodiaptomus papillopedis Fernando & Hanek, 1976: 82-88, figs 1-8.

Type locality: Unspecified locality in Karnataka State, South India.

Female

Rostral spines stumpy and triangular. General body form as in M. pseudohebes. Fourth

and fifth pedigers fused. Metasomal wings lying close to proximal lateral margins of genital

double-somite, posteriorly directed and asymmetrical, left wing being narrower and somewhat

longer than right; each wing with 2 small hyaline spines. Urosome of 2 somites. Genital double-

somite only about 1.4 times as long as anal somite and caudal rami combined, slightly dilated

subproximally with 1 hyaline spine on either side. Caudal rami symmetrical, 1.3 times as long as

maximum width and with hirsute inner margins; setae as in M. pseudohebes Ranga Reddy. P1-P4

also similar to M. pseudohebes Ranga Reddy, but for segments of rami and spinose papillae on

P2-P4 being somewhat more elongate.

Fifth legs. Coxa ornamented with spinules on posterior face besides bearing small hyaline

spines halfway near lateral margin; Basis and end claw relatively slender; basis also provided

with some spinules near inner margin and also near base of endopod.

Male

Metasomalwings and their spines much reduced. Urosome straight, narrowing but little

behind. Grasping antennule with spine on each of segments 8 and 10-13. Spinous process on

antepenultimate segment stout, somewhat inflated subproximally and distally alone, and

131

slightly shorter than succeeding segment. Right P5: coxa almost as in M. pseudohebes. Basis

roughly rectangular, with 2 irregular longitudinal rows of spinules on and near proximal inner

margin, and 1 sensory seta near disto-outer corner; mid-distal region producing into hook-like

spinous process that is clearly visible in lateral view. First exopodal segment as in M.

pseudohebes, but for the 2 hyaline lobes being much reduced. Second segment almost oval in

outline and with strong, triangular, spinous process near proximal outer corner of posterior plane;

lateral spine short, acutely pointed and placed far distally. End claw sickle-shaped, smoothly

arched, finely serrate along inner margin, and with recurved and blunt tip. Endopod slightly

longer than basal width, reaching posterior border of first exopodal segment and bearing

transverse row on spinules of rounded tip. Left P5: coxa ornamented as figured, and with small

hyaline spine. Basis squarish, with hyaline lobe halfway on inner margin and sensory seta near

disto-outer region. First exopod narrowing distally, and fringed with short hair. Second segment

and apical processes borne by it as in M. pseudohebes except for the plate-like process being

slightly different in form and serrate along inner margin only, and spinous process being

relatively stout, carrying about 9 spinules, restricted mostly to disto-outer margin. Endopod as

long as first exopod, slightly bending inward and narrowing distally; apical region ornamented.

Remarks

M. hebes can be readily distinguished from its congener by the following characters: on

female P5, coxae are ornamented, and endopods are shorter than first exopod, on male P5, left

coxa is ornamented, and the triangular spinous process on the second exopod of right P5 is

distinctly proximal.

Conservation Status: DD

132

Genus Eodiaptomus Kiefer, 1932

Eodiaptomus : Kiefer, 1932a: 473: Bayly, 1966: 127; Shen & Song, 1979: 143; Dussart &

Defaye, 1983: 91; 2002: 111; Borutzky et al., 1991: 429; Ranga Reddy, 1994: 86 -98.

Generic diagnosis

Animals slender, about 1 mm long. Female: lateral wings of fifth pediger generally small;

urosome of 3 somites; antennules long, extending beyond the end of caudal setae; on P5, lateral

spine on exopod 2 absent, endopod 1- or, rarely, 2- segmented, apex pointed and without apical

setae, and end claw with smooth or spinulose margins. Male: right caudal ramus generally

without chitinous tooth on ventral side: spinous process on antepenultimate segment of right

antennule long and staff- like or, sometimes, short and claw-like; on right P5, endopod strongly

built and with, or sometimes, without plate-like structure at distal inner corner; lateral spine on

second exopod segment inserted characteristically near the base of end claw; on left P5 second

exopodal segment with digitiform process and modified seta apically.

Type species: Eodiaptomus lumholtzi (Sars, 1889)


Eodiaptomus japonicus (Burckhardt, 1913)

Eodiaptomus sinensis (Burckhardt, 1913)

Eodiaptomus wolterecki Brehm, 1933

Eodiaptomus draconisignivomi Brehm, 1952

Eodiaptomus shihi Ranga Reddy, 1992

Eodiaptomus sanuamuangae Ranga Reddy & Dumont, 1998

Eodiaptomus phuphanensis Sanoamuang , 2001

Eodiaptomus indawgyi Dumont & Green, 2005

133

Eodiaptomus phuvongi Sanoamuang & Sivongxay, 2005.

E.shihi alone was encountered in the present survey

Eodiaptomus shihi Ranga Reddy, 1992

(Figs 90-95, Pl. 37)

Eodiaptomus shihi Ranga Reddy, 1992: 1-11, Figs 1-66; 1994: 86-98, Figs 518 -536; Dussart &

Defaye, 2002:113.

Type locality: Gandhisagar reservoir in the Mandsaur district of Madhya Pradesh State, central

India.

Body size. Female 0.9 - 1.33 mm; male .0.8 - 1.1 mm.

Female (Figs 96 -97, Pl. 37a, b)

Lateral wings of fifth pediger generally strongly asymmetrical: left wing longer than right

wing and highly variable in size and shape. Genital double-somite only slightly longer than

succeeding 2 somites plus caudal rami, symmetrical, proximal part dilated and with minute

dorsolateral spine on each side; in lateral view, the somite somewhat crenulate. P5: coxal spine

large, conical. End claw with bare, almost straight lateral margins and without proximal lateral

spine. Third segment small but distinct. Endopod sturdy, 2-segmented and slightly longer than

first exopodal segment.

Male (Figs 92-94, Pl. 37c-h)

Fourth and fifth pedigers separate. Genital somite armed at right posterior corner with

slender spine, reaching about midlength of succeeding somite. Caudal rami almost symmetrical,

1.6 times as long as wide; right ramus armed with small, tooth-like, chitionus structure near

ventro-distal region. Right antennule: spine present on each of segments 8 and 10 -16; spinous

process on antepenultimate segment generally slender, staff-like, extending to midlength or so of

134

terminal segment and highly variable in shape and size. Right P5. basis with tooth-like spinous

process or a crescentic hyaline lobe, near proximal inner corner and without any hyaline lobe on

inner margin. First exopodal segment produced in to massive spinous process at distal outer

corner. Second segment with strong lateral spine, located distally near the base of end claw.

Endopod large, generally obpyriform, 0.6 as long as second exopodal segment, inner margin

with fine spinules instead of serrations. Left P5: Endopod indistinctly 2-segmented, with

obliquely truncate apex.

Remarks

E. shihi is only the sole representative of Eodiaptomus from India and it is distinct from

all its congeners in the following characters: in female, the left metasomal wing relatively

strongly developed, though variable, and in P5, the endopod is 2-segmented and longer than first

exopodal segment; in male, the right caudal ramus has a tooth-like chitinous structure, perhaps

suggesting a close affinity of the genus Eodiaptomus to the genus Neodiaptomus Kiefer, 1932;

on right P5, basis without hyaline lobe on inner margin, and first exopodal segment is produced

into a remarkably large spinous process, and end claw is characteristic in shape. Another

noteworthy feature is the endopod of right P5 in male is always devoid of serrations on its inner

margin. Though Kiefer (1932a) mentioned the presence of these serrations as one of the generic

characters of Eodiaptomus, Bayly (1966) already raised apprehension about its reliability, having

found it wanting in a population of E. lumholtzi in Australia.

In E. shihi the third endopodal segment on P2-P4 has six setae instead of seven, exactly

as in E. lumholtzi, E. japonicus, and E. sinensis. Such reduced setal armature in all these species

is perhaps suggestive of their rheophil tendency as in Allodiaptomus raoi. In male right P5 the

basis is armed with a tooth-like structure. This feature together with the long spinous process on

135

the antepenultimate segment of grasping antennule, E.shihi closely resembles E.

draconisignivomi (Ranga Reddy, 1992). The spinous process on the antepenultimate segment of

the male right antennule shows a high degree of variation in shape and size. Similarly, the outer

spinous of the male P5 basis and also the shape of the end claw of the same appendage are also

subject to variation. What was depicted by Ranga Reddy (1992) as a tooth-like structure on the

same segment has also been observed to vary; sometimes it is in the form of a crescentic hyaline

lobe.

Distribution. E. shihi appears to be endemic to Madhya Pradesh State, Central India.

Ecology

E. shihi seems to prefer slow-flowing waters and river-fed ponds and reservoirs. Its

occurrence in completely isolated, rain-fed, standing waters is hardly likely, It may be treated as

an ecological equivalent of rheoplanktonic Allodiaptomus raoi (Ranga Reddy, 1992)


136

Genus Spicodiaptomus Rajendran, 1979

Generic diagnosis:

Animals stout and long. Metasomal wings reduced in size and asymmetrical. Metasomal

wings, genital segments, and coxa of P5 in both sexes lacking prominent spines. Second

exopodal segment of right P5 in male with a single lateral spine midway, and an accessory spine

on posterior face opposite the lateral spine. Second exopodal segment of left P5 in male armed

apically with an outer plate-like structure and an inner modified seta.

Type and only species: Spicodiaptomus chelospinus Rajendran, 1979

Spicodiaptomus chelospinus Rajendran, 1979

(Figs 96-99, Pl. 38)

Female (Fig. 96, 97a-d, Pl. 38a-c)

Total length excluding caudal setae 2.3 mm. Fourth and fifth pedigers fused; metasomal

wings conspicuous, symmetrical; right wing only slightly wider than the left, each wing with a

pair of unequal hyaline spines, the outer spine relatively longer than the inner (Fig. 96a).

Urosome of 3 somites. Genital double-somite longer than succeeding 2 somites plus

caudal rami; symmetrical; proximal part wider and with a pair of minute, dorsolateral spines;

incompletely divided by a septum arising from about the mid-length of right margin and

traversing up to mid-dorsal region; postero-dorsal border characteristically crenate, with about

four roughly semicircular small lobes. Second urosomite smallest and partly telescoped into

genital double-somite. Caudal rami parallel, symmetrical, 1.5 times as long as wide, with coarse

hair along outer and inner margins.

137

Antennule 25 segmented, extending up to about posterior margin of genital double-

somite. Seta on segment 11 modified, being geniculated as illustrated. Other cephalic

appendages as well as natatory legs are typical of subfamily Diaptominae.

P5 symmetrical; coxa large, with a small, conical, hyaline spine on posterior surface near

outer distal margin. Basis much smaller than coxa, and with a short, delicate sensory lateral seta.

First exopodal segment twice as long as wide. Second exopodal segment with short spine at

disto-lateral corner; end claw moderately stout, both margins with close-set spinules. Third

exopodal segment defined at base, slightly longer than wide, and with 2 spines, inner spine

serrated and about 3 times as long as outerl spine. Endopod unsegmented, reaching 2/3 length of

first exopodal segment, and apex with a close-set row of spinules.

Male (Figs 97f-k, 98, Pl. 38d-j)

Total length excluding setae 1.98 mm. Suture between pedigers 4 and 5 complete,

Metasomal wings (Figs. 97a) short, narrow; right wing a little longer than left one, and directed

laterally; each wing with 2 small unequal spines. Urosome 5-merous, posterior part somewhat

curved to right side. Genital somite asymmetrical, slightly dilated postero-laterally, indented at

left posterior corner, and with no spine on right side. Caudal rami twice as long as wide; right

ramus somewhat longer than left ramus; inner margins of rami hirsute. Right antennule with

spines on segments 8, 10-16; the spine on segment 13 longest, relative lengths of spines in

decreasing order as follows; 13>11>14>10>15>16>8>12; spinous process on antepenultimate

segment strong, recurved, and shorter longer than succeeding segment.

P5: right leg strongly built. Coxa wider than long, with a small, conical, hyaline spine

near distal outer corner on posterior face; a large, acute, hyaline lobe arising from mid-inner

138

margin of posterior face and arching over coxa of left leg. Basis stout, longer than wide, with a

small hyaline lobe halfway on inner margin, and a seta near outer distal corner. First exopodal

segment over twice as wide as long, with a large, broadly triangular, hyaline lobe near inner

distal region, and a small lobe at broadly triangular, hyaline lobe near inner distal region, and a

small lobe at inner distal corner; outer distal corner produced into a short spinous process.

Second segment 1.7 times longer than maximum width at midlength; outer margin convex, inner

margin moderately concave, somewhat narrow distally, armed with a crescentic hyaline lobe

near inner proximal region on posterior face, and 2 spines: lateral spine slightly shorter than the

segment, arising form mid-outer margin, almost straight, tapered off to a point, and finely

serrated, and an accessory spine, about 1/3 as long as lateral spine, arising opposite the lateral

spine at midposterior face of the segment. End claw equaling basis and exopod in length, gently

arched with recurved terminal part ending in a sharp point, and with fine spinules along distal ¾

inner margin. Endopod 1-segmented, narrow, undefined at base, slightly less than half length of

first exopodal segment, apex rounded with a row of spinules, and minute spine on either side.

Left P5: coxa with a minute conical spine at about mid-distal region on posterior face.

Basis broader than long with a small hyaline lobe on inner margin. Exopod 2-segmented;

proximal segment over twice as long as distal segment; distal segment with 2 apical processes:

an outer process that is roughly triangular, plate-like, with serrated distal inner margin and apex,

and an inner process, longer than outer one, greatly dilated proximally but drawn out in to a

strong spiniform; Endopod large, 2-segmented, reaching midway of second exopodal segment.

139

Remarks

As observed by Ranga Reddy (1985), S. chelospinus has some kinship with Kiefer‘s

(1936) Megadiaptomus pseudohebes in the follwing characters: (i) large body size, (ii) reduced

size and asymmetry of metasomal wings, (iii) lack of prominent spines on metasomal wings,

female genital segments, and coxa P5 of both sexes, (iv) exopods of female P5, and (v) size of

endopods of male P5. However, the differences associated with the nature of the outer-edge

spines of the exopodal segments of legs 2-4, the armature of the grasping antennule, and

structure of male leg, particularly the size and position of the lateral spine, make them distinct at

the generic level.

The highly variable accessory spine on the second exopodal segment of the male right P5

is inserted somewhat close to the lateral margin (cf. Ranga Reddy, 1985).

140

Genus Keraladiaptomus Silva, Kakkassery, Maas & Dumont, 1994

Keraladiaptomus Silva, Kakkassery, Maas & Dumont, 1994: Dussart & Defaye, 1995: 182;

2001: 218; 2002: 113.

Generic diagnosis:

Right male P5: lateral spine of second exopodal segment inserted near end claw; endopod

with strongly tapering subapical innermargins. Male left P5: second exopodal segment with outer

blunt digitiform structure and inner modified seta, both of equal length; endopod large 2-

segmented and tapering distally. Female: slender with strongly pointed, well-developed wings on

fifth pediger; P5: first exopodal segment long and narrow; endopod 1-segmented with an oblique

row apical spinules; second exopodal segment with slender end claw, and short lateral spinous

process; third exopodal segment rounded and armed with inner characteristically long, naked

hook-like spine and outer short spinous process.

Type and only species: Keraladiaptomus rangareddyi Silva, et. al., 1994.

Keraladiaptomus rangareddyi Silva, Kakkassery, Maas & Dumont, 1994

(Figs 100, 101)

Keraladiaptomus rangareddyi: Silva et. al., 1994: 119-128; Figs 1-38; Dussart & Defaye 2001:

218; 2002: 113.

Type locality: temporary pond at Kuttappam Kulam pond at Mattan village, Trichur District,

Kerala State.

Male

First urosomite with slender spine on each side; fourth one with asymmetrical posterior

border. Caudal rami with hirsute inner margins. Right antennule with spine on segment 8, 10 11,

13 and 15. Largest spine on segment 13, small and thin ones on segments 10 and 11, still smaller

141

spines on segments 8, 12 and 15, digitiform process on antepenultimate segment shorter than

next segment.

P5: coxa of each leg with hyaline spine on conical outgrowth. Right P5 basis almost

twice as long as broad, with small pointed membrane on inner distal edge and sensory seta on

outer distal corner. First exopodal segment narrow, with series of triangular sclerotized

projections on distal margin; outer distal corner produced into moderate spinous process; second

segment almost rectangular, 2.5 times as long as broad; lateral spine slender, inserted close to

end claw, serrated along inner distal half; end claw long, slender, swollen at its base, slightly

incurved and serrated over most of its length; endopod strongly tapering towards apex, with

subapical row of spinules and small pointed outgrowth halfway.

Left P5 basis with rounded ear-like membrane on inner edge. Exopodite 2-segmented,

with long first and short, almost round, second segment, both lined with hairy cushions on inner

side. Second segment ending in 2 processes of similar length: external, blunt, finger-like

projection, lined with 1 inner row of small spines and internal, more pointed projection, lined

with 2 rows of small spines, tapering distally. Endopodite 2-segmented, first segment short, with

minute hyaline membrane at inner distal corner; second segment longer, slightly tapering,

apically ornamented with oblique row of spinules.

Female

Wings of fifth pediger developed and bilobed, outer lobes produced into a spinous

process. . Urosome of 3 somites; genital double-somite twice as long as broad, subproximal part

asymmetrically dilated; left side slightly rounded with small, distally-directed spine; right side

more protruding, with small, laterally directed spine. Furcal rami symmetrical, with setules on

external and interal margins. Antennules, almost reaching posterior end of second urosomite. P5:

142

coxa with laterodistal spinous projection on posterior side and group of long, latero-proximal

hair like spinules on anterior side; first exopodal segment long and narrow, cylindrical, 3.6 times

as long as broad; end claw spinulated lateral margins; second exopodal segment produced at

outer distal corner into pointed, strong, lateral spine of moderate length; third segment bearing

rather large rounded segment, tapering on outer distal corner into pointed spine and carrying at

midlength unusually long naked spine, with hook-like incurved tip. Endopod 1-segmented, but

with slight indentation on inner edge, overreaching midlength of first exopodal segment, with

rounded apex and subapical, oblique row of spinules.

Remarks

This species stands out in the family especially by the very long hook-like prehensile seta

on the third exopodal segment of the female P5. Even the first exopodal segment of the same

appendage also is unusually long and slender.

Distribution

Apart from type locality this species was found in Monastery pond on the Christ college

campus, Irinjalakuda town, Kerala.

143

Acanthodiaptomus Kiefer 1932

Generic diagnosis (Dussart & Defaye, 2001)

Maxilliped poorly developed. Right male antennule with very long spiniform extension

on segment 13 and with usual spines on segments 8, 10, 11, 15 and 16. Last segment with small

beak-like extension. Right male P5 with very small endopod; exopod 1 with rounded corners.

Left P5 male with exopod ending in spherical structure covered by papillae, produced into an

apical digitiform process and roughly spiniform, lateral process. Female P5 with endopod

bearing at its end 2 thick, unequal setae and a tuft of hair-setae; exopod 3 much reduced or even

fused to exopod 2 ; in the latter case, represented by the usual spine and seta, flanked by the

usual seta of exopod 2.

Acanthodiaptomus denticornis (Wierzejski, 1887)

(Figs 102,103)

Body Size : female 1.5-30 mm ; male : 1.43-2.5 mm.

Female

Rostrum with relatively large spine, postero-lateral wings of fifth pediger symmetrical

with small hyaline spines. Urosome of 2 somite. Genital double-somite very long, slightly

dilated proximally, right side somewhat more dilated than left side. Caudal rami symmetrical,

setae very long. Antennule reaching the end of caudal rami; seta on first segment short. P2 with

Schmeil‘s organ on the middle endopodal segment. P5 hyaline spine on coxa small. Seta on

basis very short. Lateral spine on second exopodal segment very small. Third exopodal segment

tiny and completely fused with second exopodal segment. Endopod almost as long as first

exopodal segment; apex with outer subapical row of hairy and 2 unequal strong setae.

144

Male

Rostrum as in female. Thorax and urosome alomost symmetrical. Left antennule as in

female. Right antennule with spine on segments 8, 10-16; the terminal segment ending in a claw-

like structure. Antepenulatimate segment with hyaline lamella. Right P5 : coxa with very

slender hyaline spine. Basis without hyaline lamella on inner margin. First exopodal segment

characteristically produced at distal outer and inner corners. Second exopodal egment with very

long lateral spines inserted posterior to the middle. End claw weakly or slightly curved. Endopod

very small. Left P5 : basis very stumpy, without hyaline lobe on inner margin. Second exopodal

segment spherical, with short conical terminal process and a short spiniform seta on outermargin.

Ecology and distribution

A. denticornis is a Palaearctic species, confined to high-altitude water bodies (Kiefer,

1978). According to Dussart & Defaye (2002), it is distributed in Europe; Asia; Baikal; Canada:

British Columbia, Alberta, Yukon Territories. In India, Kiefer (1939) reported it only from

certain swamps and lakes (Sundar Khun, altitude 1582 m ; Manasbal Lake, altitude 1584 m ;

temperature c. 19ºC; pH 8.5-9.3) of Kashmir in association with Arctodiaptomus euacanthus.

There is hardly any record of A. denticornis from any of the elevated localities of peninsular

India.

145

Genus Arctodiaptomus Kiefer, 1932

Arctodiaptomus: Kiefer, 1932a: 471; Rylov, 1935: 247; Damian-Georgescu, 1966: 80; Dussart,

1967: 130; Kiefer, 1971: 188; Kiefer, 1978: 118; Shen & Song, 1979: 123; Dussart & Defaye,

1983: 78; Borutzky et al., 1991: 255.

Generic diagnosis:

Kiefer (1978) revised the generic diagnosis of Arctodiaptomus as follows:

Male: exopod of left P5 with slender, digitiform terminal process, close to which arises a long

seta on anterior side. Inner margin of basis of the same leg with a hyaline membrane, extending

mostly beyond the end of the segment. Basis of right P5 with differently-shaped hyaline lamella

on inner margin and often with some-what plung-like chitinous outgrowth on proximal posterior

face. Sensory spine on segment 8 of grasping antennule mostly in the form of a typical spine.

Rostrum with 2 relatively short to very strong, pointed, triangular processes of specific

significance.

Female: rostrum as in male, but without the right side hook of specific significance. Fifth pediger

with small to very large lateral wings. Setation of antennules in three different types, but always

with 2 setae on segment11. Middle endopod segment of P2 with Schmeils‘s lobe. Endopod of P5

without apical setae, only with a subapical row of hairs on the anterior aspect.

Based on the characters of the grasping antennule and male P5, Kiefer (1932a, 1932c,

1935) divided the genus into four subgenera: Arctodiaptomus s. str. Kiefer, 1932,

Rhabdodiaptomus Kiefer, 1932, Stenodiaptomus Kiefer 1932, and Haplodiaptomus Kiefer, 1935.

Subsequently, Borutzky et al. (1991) added a fifth subgenus, Mesodiaptomus Borutzky et al.

1991.

146

Arctodiaptomus (Arctodiaptomus) similis similis (Baird, 1859)

(Fig. 104)

Type locality: A pond ― Briket Mamillah‖. Jerusalem.

Body size. 1. 36-1.80mm; male 1.21-1.40mm.

Female

Lateral wings of fifth pediger relatively small, each with 2 similar, large hyaline spines.

Urosome mostly 2-merous. Genital double-somite generally very long; proximal part moderately

dilated, with strong spine on each side. Antennules extending up to middle or end of genital

double-somite; segments 11, 13, 14 and 17 with 2 setae, segments 12, 14 and 16 with 1 seta; seta

on first segment fairly long ( 200-300µm); first seta longer than other 2 setae on second segment.

Male

Fourth urosomite produced backwards on right side and armed with rows of fine spinules.

Middle part of left antennule normal; segments 9 and 11 alone with 2 setae. Right antennule:

segment 15 sometimes with smaller tooth on proximal margin; spinous process of

antepenultimate segment almost straight, slender, with hook-like apex and long hyaline

membrane. Right P5: basis relatively short, with larger hyaline lamella on inner margin. First

exopodal segment produced at distal outer corner into long spine and with 2 chitinous humps of

variable form and size on posterior face. Lateral spine of second segment long and proximal in

position. End claw sturdy and deeply bent. Left P5: Coxal spine very minute.

Variability

According to Kiefer (1979), the number of setae on segments 13, 15 and 17 of male left

antennule varies from 1 to 2 (forma saetosior).

147

Distribution

Israel, Lebanon, Jordan, Syria, Iran, Bangladesh, west coast of Caspian Sea, west

Antolia, southeast Bulgaria, Sardinia (Italy), and (?) India.

Ecology

This is the most common diaptomid in Israel. According to Dimentaman & Por (1985):

―Though it is a typical inhabitant of temporary rainpools, it also appears in permanent waters as

result of the winter floods. Salinity in these habitats is low, i.e., below 2 m S cm-1

at 20°C. Water

temperature ranges between 4◦ to 30°C.‖ The specimens show high concentration of red

carotenoids during cold season, but become almost colorless during late spring owing to decrease

in caraotenoid pigment. The above workers further observed: ―The main adaptation of A. s.

similis for living in temporary waters is the production embreyonated resting eggs, which are

able to withstand desiccation, high temperatures, intense irradiation and other unfavorable

condition of the dry season. A relatively rapid rate of maturation, with gravid females appearing

4-5 weeks after the filling of the water basin (in the Coastal Plain), is another important

adaptation to the short-lived habitats‖.

Arctodiaptomus (Arctodiaptomus) euacanthus Kiefer, 1935

(Fig. 108)

Type locality

Temporary pond near Sonamarg, alt. 2620, Kashmir, India.

Body size. Female 1.8 mm; male 1.55 mm.

Female

Lateral wings of fifth pediger quite large and asymmetrical, left wing wider and more

extensive than right wing. Urosome 3-merous; proximal part of genital asymmetrically dilated

and armed with short, thick spine on each side. Caudal rami almost twice as long as wide.

148

Antennules extending almost to end of genital double-somite. P5: coxal spine relatively short,

but very thick. End claw slender and distinctly bent. Third exopod segment strongly built.

Endopod extending up to midlength of first exopodal segment.

Male

Fourth and fifth pedigers with lateral notch as in female. Third and fourth urosomites

obliquely bent backwards to the right and ornamented with numerous fine spineless on right

dorsolateral surface. Caudal rami symmetrical and thrice as long as wide. Right antennule: spines

present on segments 10, 11 and 13-15; spines on segments 10, 11 and 13 equally longs, but that

on segment 13 stronger; spinous process on antepenultimate segment almost straight, nearly as

longs as penultimate segment and lined with smooth or serrulate hyaline membrane. Right P5:

basis quadratic with hyaline membrane, reaching slightly beyond its distal border. First exopod

segment distinctly slender, thrice as long as median width and with crescentic hyaline lobe at

about the middle of posterior surface; lateral spine extraordinarily long and strong and lying in

the proximal fourth of outer margin. End claw long, relatively thin and smoothly bent. Endopod

long, overreaching midlength of second exopodal segment. Left P5: basis with 2 contiguous

hyaline lamellae on inner margin; distal one finger-like and reaching middle of endopod.

Distribution. Sonamarg in Kashmir, North India.

Ecology

Known from temporary ponds and large swamps rich in algae and/or macrophytes line

Potamogeton crispus and Limnanthemum nymphaeoides. Altitude: 2620 m; water temperatue 10-

19.1°C; pH 7.0-9.6; season April-May.

Conservation Status: Data Deficient (DD).

149

Arctodiaptomus (Rhabdodiaptomus) michaeli Reddy, Balkhi & Yousuf, 1990

(Fig. 105)

Type locality

Alapathar Lake, Kilanmarg, alt. 3200 m, Kashmir, India.

Body length. Female 1.4-1.7mm; male 1.2-1.3 mm.

Female

Fourth and fifth pedigers notched laterally. Lateral wings of fifth pediger moderate in

size and asymmetrical; left wing distinctly larger, posteriorly directed, attenuating apically and

extending almost up to left genital spine; right wing triangular and posterolaterally directed.

Urosome of 3 somites; genital double-somite incompletely divided at midlength; proximal part

asymmetrically dilated and armed with small spine on each side. Caudal rami 2.7 times as long

as wide and with hairs along both margins; setae slightly dilated proximally. Antennules

extending nearly up to midlength of genital double-somite; segments 9, 11, 13, 15-17 and 22-24

with 2 setae; seta on first segment 300-360µm long. P1: spine on first exopodal segment setiform

and unusually long, equaling combined length of second and third segments. P5: as in Fig. 105h.

Male

Fourth and fifth pedigers separate. Genital double-somite with minute sensory spine on

each side. Caudal rami nearly symmetrical, somewhat dilated apically, 4 times as long as median

width and smooth. Right antennule: segments 8 and 10- 13 with spine each; spine on segment 10

longest followed in decreasing order by spines on segments 11, 8, 13 and 12; spinous process on

antepenultimate segment nearly straight, staff-like and shorter than penultimate segment. P1:

spine on first exopod segment long, as in female. Right P5: basis produced into short, thumb-like

process at proximal inner corner and with large hyaline lobe on inner margin. Second exopodal

segment with relatively large, triangular lobe just below lateral spine; lateral spine slightly

150

shorter than the segment. End claw with recurved tip. Left P5: basis with long, narrow hyaline

lamella, extending beyond its distal border.

Distribution. Kashmir, India.

Ecology

Ranga Reddy et al. (1990) recorded this species in two Kashmir lakes: Alapathar Lake,

Kilanmarg; (altitude 3200 m; temperature: air 8°C, water 12°C; pH 6.93; dissolved oxygen 6.8

mg1-1). Marsar Lake, upper Dacigam (altitude 3600 m; temperature: air -2°C, water 9°C; pH

7.54; dissolved oxygen 7.2 mg1-1). There are no subsequent records of this species.

Arctodiaptomus (Rhabdodiaptomus) salinus (Daday, 1885)

(Fig. 111)

Type locality

Turda, Cluj Province, Romania.

Body size

Female 1.0-1.8 mm; male 1.0-1.7 mm.

Female

Rostral spines well developed, slender. Lateral wings of fifth pediger small, slightly

asymmetrical. Urosome of 3 somites. Genital double-somite slightly dilated subproximally and

somewhat asymmetrical; right spine perpendicular to the somite, left spine postero-laterally

directed. Caudal rami longer than anal somite; setae normal. Antennules long, extending

sometimes up to end of caudal setae; segment 11 with 2 setae, segments 12-17 with 1 seta each;

seta of first segment as long as first 3 to 5 segments. P5: coxal spine short and strong. First

exopodal segment slender. Inner spine of third exopod segment 2/3 as long as end claw. End

claw almost straight.

151

Male

Rostral spines somewhat smaller than in female. Right wing larger than left wing. Third

and fourth urosomites with rows of dorsal spinules. Left antennule as in female. Right one with

slender spines on segments 8, 10, 11 and 13; segments 14-16 unarmed; spinous process on

antepenultimate segment staff-like, longer than penultimate segment, but often reaching even

antennular tip. Right P5: coxal spine quite large. Basis with highly distinctive chitinous process

on proximal posterior surface; hyaline membrane on inner margin hardly reaching end of

segment. First exopodal segment produced at distal outer corner into long and sturdy spinous

process. Second segment with 1 large hyaline process near the base of lateral spine; lateral spine

roughly as long as the segment and lying proximal to the mid-outer margin. End claw distinctly

sickle-shaped. Endopod with undulated inner margin left P5: coxal spine very minute. Basis with

small hyaline membrane at about the mid-inner margin.

Ecology and distribution.

A. salinus is a halophilous species that seldom occurs in freshwater. It is both

eurythermal (6-34°C) and euryhaline (2 to 15 g of chloride, or upto 14 g of sulphate per liter),

occurring in water bodies of all dimensions. It is a characteristic species of plankton of saline

waters of semi-desert region (steppes) and brackish water. The geographic range extends to

countries around the Mediterranean and also steppes and deserts up to central Asia: North Africa

(Egypt; Algeria; Tunisia; Morocco, Tiselit Lake, above 2000 m); Central Asia (Caspian region,

Tibet, Turkey, Syria, Palestine, Iran, Pakistan, India, Mongolia, China); Europe (Spain, France,

Germany, Romania, Bulgaria, Yugoslavia, Hungary, European Russia, Italy).

Ecology and Biology

Conservation Status: Data Deficient (DD)

152

Arctodiaptomus (Stenodiaptomus) stewartianus (Brehm, 1924)

(Fig. 106)

Type locality

Lake Raham Tso and a water body in the Gyantse valley, Tibet.

Body size. Female 1.3 -1.5 mm; male 1.2 mm.

Female

Lateral wings of fifth pediger relatively small but strikingly asymmetrical; left wing

wider and more extensive than right wing and directed backwards; right wing narrow and

directed laterally. Genital double-somite nearly as long as rest of urosome including caudal rami;

subproximal part almost symmetrically dilated, armed with long, slender spine on each side;

right distal corner with slight swelling. Caudal rami almost twice as long as wide. Antennules

extending to about distal border of genital double-somite. P5: coxal spine distinctly long, slender,

extending beyond distal border of basis. First exopod segment 2.5 times as long as wide; distal

inner corner somewhat dilated. Second segment with very small lateral spine. Endopod quite

small, extending to midlength of first exopodal segment.

Male

Right antennule with spine on each of segments 10, 11 and 13; spine on segment 13

largest, obliquely bent and reaching beyond midlength of 14th segment; antepenultimate segment

without spinous process, but with long, very narrow, smooth or finely serrate hyaline membrane,

or the hyaline membrane may be absent. Right P5: basis expanded distally, with unusually large,

spherical hyaline outgrowth at mid-inner margin, a chitinous lobe near proximal inner corner and

another large, hyaline lobe at distal inner corner. Second exopodal segment proximally dilated

and distally much attenuated; outer margin of attenuated part with 2 round, chitinous projections,

and large hyaline lobe near the base of lateral spine; lateral spine strong, lying proximal to the

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middle of outer margin and with coarsely denticulate inner margin. End claw extraordinarily

strong, sharply bent beyond midlength, and nearly of the same width throughout. Endopod 1-

segmented, very elongate, almost reaching end of second exopodal segment. Left P5: basis with

small hyaline outgrowth on distal inner margin.

Distribution

North India: several lakes in the Tibetan region, viz. Tsar Tso, Pangur Tso, Mitpal Tso,

Yaye Tso and Tso Moriri; China: north-western and southern Tibet.

Ecology

Known from small to very large lakes (alt. 4252-4875 m), often infested with littoral

plants such as Potamogeton pectinatus. Water temperature 11.7 -15.1°C; pH 8.7-9.6. Collected

in the months of June and August.


Arctodiaptomus (Stenodiaptomus) altissimus altissimus Kiefer, 1936

(Fig. 109)

Type locality

Ice-covered Lake Ororotse Tso, just south of Chang-chenmo River, altitude 5297 m,

Ladak, India.

Body size. Female 1.5 mm; male 1.4 mm.

Female

Lateral wings of fifth pediger strongly asymmetrical: left wing almost oval in outline,

right wing narrow with distal half being elongate and bent outwards. Genital double-somite

almost as long as rest of urosome including caudal rami and asymmetrical, left side only slightly

dilated at the middle, provided with small hyaline spine; right distal corner of the somite also

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produced into finely ornamented, small lobe. Caudal rami about twice as long as wide.

Antennules extending beyond caudal setae. P5: coxal spine extraordinarily long, reaching

beyond posterior border of basis and outcurved. First exopod segment slender, straight, nearly

thrice as long as wide. Second segment with characteristic minute spine at distal outer corner.

Third segment small. Edopodite 1-segmented, almost cylindrical, about 0.4 as long as first

exopodal segment.

Male

Fourth urosomite produced at right distal corner into small lobe. Caudal rami

symmetrical. Right antennule with spines on segments 10, 11 and 13; spine on segment 13 very

long and lying perpendicular to the long axis of the appendage; antepenultimate segment with

extremely narrow, distal hyaline membrane. Right P5: basis with large, almost spherical hyaline

lone at mid-inner margin, a strong, somewhat triangular chitinous outgrowth near proximal inner

corner and a third long, curved (in lateral view), chitinous outgrowth at about mid-posterior

surface of the segment. Second exopod segment elongate and characteristic in shape and

chitinous ornamentation; lateral spine very long, slender, doubly curved and lying in the

proximal fourth of outer margin. End claw strong, almost of equal width all along, with minute

tubercle at base on outer margin. Endopod very long, reaching base of end claw. Left P5: basis

with somewhat large hyaline outgrowth at distal inner corner.


North India. Known from Ororotse Tso, and ice-covered eutrophic lake (alt. 5297 m), just

south of Chang- chenmo river in the Tibetan region.


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Arctodiaptomus (Haplodiaptomus) parvispineus Kiefer, 1935

(Fig. 107)

Type locality

A pond at Chushol, south of Panggong Tso, altitude 4491 m, Ladak, India.

Body length. Female 2. 06 mm, male 1.70-1.75 mm.

Female

Lateral wings of fifth pediger relatively large, asymmetrical right wing distinctly smaller

than left wing and laterally directed. Genital double-somite shorter than rest of urosome

including caudal rami and asymmetrically dialted, with larger lobe on right side; genital spines

minute. Caudal rami elongate, about thrice as long as wide; left ramus slightly longer than right

one. Antennules extending to about the end of middle urosomite (details of armature no known).

P5: coxal spine short, thick and blunt. First exopod segment twice as longas wide. Third segment

small. Endopod about half as long as first exopodal segment.

Male

Fourth and fifth pedigers distinct. Caudal rami somewhat slenderer than in female. Right

antennule: segments 10, 11 and 13 with spine each; spine on segment 13 strikingly short;

antepenultimate segment without spinous process. Right P5: basis with spherical chitinous hump

near proximal inner margin and large hyaline lamella on distal margin. First exopodal segment

produced at distal outer corner into short, blunt spinous process. Second segment plump, 1.5

times as long as wide, with large chitinous outgrowth on posterior surface, visible more clearly

in lateral view; lateral spine slender, shorter than segment and distal to middle of outer margin.

Endopod cylindrical, extending to midlength of second exopodal segment. Left P5: basis with

narrow hyaline membrane. Endopod 1-segmented and plump.

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Indian Tibet: ‗Cushol, south of Panggong Tso, 4491m above level‘. It occurs in pools and

ponds with large algal colonies.


phylum arthropoda subphylum crustacea brünnich, 1772

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