taxonomic notes on catfishes of travancore...jzbr copy

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Journal of Zoological and Bioscience Research, 2015, 2, 3:6-17

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Taxonomic notes on the catfishes of central Travancore of Kerala, India

Mathews Plamoottil

Asst. Professor in Zoology, Baby John Memorial Government College, Chavara, Kerala Correspondence email: [email protected]

_____________________________________________________________________________________________ ABSTRACT The present study was conducted to analyze the taxonomic details of catfishes occurring in water bodies of central Travancore of Kerala, India. Catfishes collected from different stations of various aquatic bodies of Travancore; 21 species of fishes belong to the genera Batasio, Horabagrus, Pangasinodon, Mystus, Ompok, Wallago, Pseudotropius, Glyptothorax, Clarias, Heteropneustes and Arius were collected from various locations. They were undergone detailed taxonomic studies. Keywords: Freshwater fishes, Silurids, Taxonomy, Meristic counts, Metric characters. _____________________________________________________________________________________________

INTRODUCTION

The catfishes, belong to an unusually well defined order Siluriformes, constitute 1/3 of the freshwater fish fauna of the globe. Most of them occur in abundant numbers and are the second or third fishes of abundance in India. Many scientists have showed much interest in the study of phylogeny and taxonomy of catfishes. The publication of five volumes on Catfishes of the world by Davis Sands is of interest to aquarists all over the world. The studies by Bornbush [1], Ferraris and Pinna [2] and Ferraris [3] on Siluridae, Mo [4] on Bagridae and de Pinna [5] [6] on Sisoridae are much relevant. Taxonomic works on catfishes of India by Misra[7], Jayaram & Sanyal [8] and Jayaram [9] are authentic books indispensable for any student of ichthyology. Batasio, Horabagrus, Mystus, Ompok, Glyptothorax, Clarias, Horaglanis, Heteropneustes, Pseudeutropius, Silurus and Wallago are the catfish genera residing in the water bodies of Kerala. From the literature it was understood that no detailed taxonomic works has been conducted on catfish resources of Central Travancore of Kerala, India. So it was an endeavor to study the taxonomy of catfishes of Travancore.

MATERIALS AND METHODS

Different species of catfishes were collected from selected stations of central Travancore using different types of gears such as gill net, cast net, madavala, vattavala etc. Selection of these gears is based on its fishing efficiency in a running water body. Collected fishes were cleaned with water and kept in 10% formalin. After fixation they were taken out, identified and taxonomically analyzed. Abbreviations Used:D-Dorsal fin rays; A- Anal fin rays; V- Ventral fin rays; P-Pectoral fin rays; C- Caudal fin rays; TL- Total length; SL- Standard length; HL- Head length; BD / BDD- Body depth at rayed dorsal fin; BDA- Body depth at anal fin; BDAD- Body depth at adipose dorsal fin; BWAD- Body width at adipose dorsal fin; BWD- Body width at dorsal fin; BWA- Body width at anal fin; HD- Head depth; PRD- Pre dorsal length; POD- Post dorsal length; PRP-Pre pectoral length; PRPL- Pre pelvic length; PRA-Pre anal length; LRD- Length of rayed dorsal fin; LBRD-Length of base of rayed dorsal fin; LBAD-Length of base of adipose dorsal fin; LBA-Length of base of anal fin; LP-Length of pectoral fin; LDSP- Length of dorsal spine; LPSP-Length of pectoral spine; LPL-Length of pelvic

Mathews Plamoottil J. Zool. Biosci. Res., 2015, 2 (3):6-17 ______________________________________________________________________________


fin; LCP-Length of caudal peduncle; DCP-Depth of caudal peduncle; WCP- Width of caudal fin; LA-Length of anal fin; LAD-Length (height) of adipose dorsal fin; LBPL- Length of base of pelvic fin; LBP-Length of base of pectoral fin; DAV- Distance from anal to vent; DVV- Distance from ventral to vent; DRD & AD- Distance from rayed dorsal to adipose dorsal fin; DP-PL- Distance from pectoral to pelvic; DPL-A- Distance from pelvic to anal; DA- C- Distance from anal to caudal; LATA- length of adhesive thoracic apparatus; WATA- Width of adhesive thoracic apparatus; LUCL- Length of upper caudal lobe; LLCL- Length of lower caudal lobe; ; DO- ST-Distance from occiput to snout; DO-D- Distance from occiput to dorsal fin; HW- Head width; ED- Eye diameter; IOW-Inter orbital width; INW- Inter narial width; STL-Snout length; WGM- Width of gape of mouth; LMB-Length of maxillary barbels; LNB-length of nasal barbels; LOMB-Length of outer mandibular barbels; LIMB-Length of inner mandibular barbels.

RESULTS AND DISCUSSION

Twenty one species of catfishes were collected from various selected sites of Travancore during 2010- 2012 (Table 1 & Fig. 1 – 20). Of different species of fishes collected, species of genus Mystus outnumbered all others. Seven new catfishes were discovered, named and described during this study; they belong to the genera Batasio, Horabagrus, Mystus and Glyptothorax. Culturable fishes are Pangasinodon hypothalamus, Clarius gariepinus, Wallago attu and Heteropneustes fossilis. The first two are exotic. Arius subrostratus is an estuarine fish might have been ascended from Vembanad Lake. All the fishes except Batasio travancoria, B. flavus and Glyptothorax elankadensis are edible. Batasiotravancoria Hora and Law

Fig. 1.Batasio travancoria Fig. 2.Batasio flavus Batasio travancoria Hora & Law, 1941, Rec. Indian Mus. 43 (1): 40 (type locality: Perumthenaruvi, tributary of Pamba River at Edakadathy, Kerala). Diagnosis: Body with a narrow dark streak along lateral line; a triangular spot present at the caudal peduncle. Many pores and skin folding present on the head region. Barbels not extending beyond eyes; a distinct depression, shaded by a bluish black color present on humeral region; a black line present in between humeral and caudal blotches. Meristic counts: D- I, 7; A- 12; V-I, 5; P-I, 7; C-16. Metric Characters: TL (mm)- 86.0; SL (mm)- 70.0; HL (mm)- 16.0.% SL: BD- 20.0; HL- 22.9; HD-17.1; PRD-38.6; POD- 65.7; PRP-50.0; PRA-74.3; LD-14.3; LBRD-12.8; LBAD- 28.6; LBA-15.7; LP-12.8; LPL-14.3; LCP-15.7; DCP-12.1; LA-8.6; LAD-1.4; LBPL- 4.3; LBP- 4.3. % HL: HD- 75.0; ED- 15.6; IOW- 37.5; STL- 43.8; LMB- 43.8; LNB- 25.0; LOMB-18.8; LIMB-9.4. Other features: Live fishes have a dark pink color; ventral side yellowish white; ventro lateral side of the body has minute distinct black spots; all fins, except ventral, have a moderate dark shade. Pectoral spine deeply serrated behind; its outer side granulated or only very finely serrated; caudal lobes have unequal length. Adipose dorsal present on a thin long ridge; its length of base greatly longer compared to all other fins.



Table 1.Synonyms. systematic position and common names of the catfishes of Central Travancore

Sl. No.

Name of Species Synonyms Order Family Common Name

1 Batasio travancoria Nil Siluriformes

Bagridae, Bagrinae

Travancore Batasio

2 Batasio flavus Nil Siluriformes

Bagridae, Bagrinae

Yelow Batasio

3 Horabagrus brachysoma

Pseudobagrus brachysoma Pseudobagrus chryseus

Macrones chryseus

Siluriformes

Bagridae, Bagrinae

Gunther’s catfish

4 Horabagrus melanosoma

Siluriformes Bagridae, Bagrinae

Black Horabagrus

5 Pangasinodon hypothalamus

Nil Siluriformes Pangasidae

6 Mystus oculatus Bagrus oculatus Macrones oculatus

Siluriformes

Bagridae, Bagrinae

Malabar Mystus

7 Mystus gulio Pimelodus gulio Macrones gulio

Siluriformes

Bagridae, Bagrinae

Long- whiskered

catfish, Shadow cat fish

8 Mystus keralai Nil Siluriformes

Bagridae, Bagrinae

Long- whiskered Kerala catfish

9 Mystus heoki Nil Siluriformes

Bagridae, Bagrinae

Elongated Kerala Mystus

10 Mystus menoni Nil Siluriformes

Bagridae, Bagrinae

Idukki Mystus

11 Mystus indicus Nil Siluriformes

Bagridae, Bagrinae

Central Travancore

catfish 12 Mystus canarensis Hara malabarica Siluriformes

Bagridae, Bagrinae

Nil

13 Ompok malabaricus Silurus malabaricus Callichrous malabaricus

Silurus goae

Siluriformes Siluridae Goan catfish

14 Ompok bimaculatus Silurus bimaculatus Callichrous bimaculatus

Callichrousmacrophthalmus Ompokcanio

Ompoksindensis

Siluriformes Siluridae Indian butter catfish

15 Wallago attu Silurus attu Wallagonia attu W. attu valeya

Siluriformes Siluridae Boal, Freshwater

shark, Shark catfish

16 Pseudotropius mitchelli

Pseudotropius sykesii Siluriformes

Schilbeidae Schilbeinae

Malabar Patashi

17 Glyptothorax elankadensis

Nil Siluriformes

Sisoridae Travancore rock catfish

18 Clarius dussumeiri Nil Siluriformes Clariidae Valenciennes’

clariid 19 Clarius garipinus Nil Siluriformes Clariidae Burchell’s

clariid 20 Arius subrostratus Pimelodus arius

Arius buchanani Tachysurus arius

Siluriformes Aridae Treadfin catfish

21 Heteropneustes fossilis Silurus fossilis Sacchobranchus fossilis

Siluriformes Heteropneustidae Stinging catfish

Batasio flavus Plamoottil Batasioflavus,Plamoottil, 2015, Journal of Research in Biology, 5 (5): 1799- 1808 (Type locality: Paduthode, Manimala River, Kerala, India) Diagnosis: It can be distinguished from its congeners in having a slender (BDD 16.0-18.0 % SL) body; flatter (HD 53.0-57.1 % SL) head; occipital process very small and hidden under skin; orbits widely set (IOW 27.0-31.3 % HL);



dorsal profile nearly straight; single median longitudinal groove on head; adipose dorsal fin with a straight margin for entire length and inserted behind a considerable distance from rayed dorsal fin. Meristic counts: D- I, 7; A- iv, 9- 10; V-5; P-I, 7- 8; C-17. Metric Characters: TL (mm)- 82.0-106.0; SL (mm)- 69.0-88.0; HL (mm)- 16.0-21.0. % SL: BD- 16.0-18.0; HL- 21.0-23.8; HD- 11.1- 13.6; PRD- 32.6-35.8; POD-63.0-65.2; PRP-21.7-23.9: PRA-65.0-68.0; LRD-13.6-17.6; LBRD-13.1-14.5; LBAD-25.0-29.0; LBA-14.2-16.0; LP-14.8-17.3; LPL-12.3-14.8; LCP- 17.2-21.7; DCP-8.6-11.6; LA-11.1-12.5; LAD-3.0- 5.0; LBPL- 3.3-4.1; LBP-3.6-4.3. Other Features: Body and fins yellow; a small brownish black triangular spot present in front of rayed dorsal fin base; a triangular dark or light brownish black spot present on caudal base. A thin brownish black line passes through mid lateral line.

Horabagrus brachysoma (Gunther) Pseudobagrus brachysoma Gunther, 1864, Cat. Fish. Brit. Mus. 5: 86 (type locality: “Cochin China” lapsuscalami for Cochin). Diagnosis: occipital process extends to pre dorsal plate; mouth sub terminal; a large round blotch present at the branchial region. Maxillary barbels extend to pectoral fin base; rayed dorsal fin with a strong, feebly serrated spine; adipose dorsal fin is short and low.

Fig. 3.Horbagrus brachysoma; Fig. 4.Horbagrus melanosoma Meristic charaters: D- I, 6-7; P- I, 8-9; V- I, 5; A- III, 20- 25. C- 17. Metric characters: TL (mm) - 214.0; SL (mm)- 175.0.% SL: HL- 28.4; HD- 17.4; HW- 20.9; BD- 22.7; PRD- 37.2; POD- 60.5; PRP- 23.5; PRA- 63.1; PRPL- 52.0; LRD- 20.6; LBRD- 9.5; LBAD- 4.4; LBA- 24.6; LP- 20.0; LPL- 11.5; DCP- 12.0; LCP- 12.5; LA- 12.6; LAD- 7.4; LBPL- 4.1; LBP- 4.9. % HL: HD- 61.4; HW- 73.6; ED- 18.7; IOW- 53.9; INW- 32.6; STL- 40.2; WGM- 48.8; LMB- 70.5; LNB- 59.3; LOMB- 65.2; LIMB- 47.6. Other features: Color dark greenish above with golden yellow flanks; dorsal and anal fins yellowish orange; caudal fin yellow; a semi lunar thick black patch present at the caudal fin base. Horabagrus melanosoma Plamoottil & Abraham Horabagrus melanosoma, Plamoottil& Abraham, 2013, Int.J. Pure Appl. Zool, 1 (4): 280-288 (Type locality: West Venpala). Diagnosis: Color black to grayish black, fins grey to black, pelvic fin does not reach anal fin and the latter with iii, 28- 30 rays. Lengths of head, dorsal fin, dorsal spine and pectoral spine shorter compared to the congeners. Meristic counts: D- II, 6; P- I, 7-8; V- i, 5; A- iii, 28- 30; C- 17.



Metric characters: TL ( mm)- 124.0-282.0; SL (mm)- 96.0-235.0. % SL: HL-21.9- 27.6; BDD-18.8- 24.0; PRD-32.7-37.0; POD-60.7- 71.4; PRP- 21.9- 24.1; PRA- 60.2-64.7; PRPL- 45.2- 51.1; LRD- 16.2-19.5; LBRD- 7.7- 8.4; LBAD- 3.8- 4.5; LBA- 23.1- 25.6; LP- 15.7- 20.1; DCP- 9.8- 10.6; LCP-8.7- 13.0; LA- 8.9- 11.0; LAD- 7.5- 8.0. % HL: HD- 59.2- 80.0; HW-75.0- 102; ED-16.7-22.2; IOW-53.0- 66.7; STL-35.2- 45.6; WGM-46.3- 57.8; LMB-51.8- 77.8; LNB-46.6- 55.6; LOMB-62.1- 77.8; LIMB- 41.4- 53.4. Remarks It is the third species of Horabagrus discovered from Kerala; it is an edible fish endemic to Kerala. Pangasinodon hypothalamus (Sauvage) Helicophagus hypophthalmus, Sauvage, H.-E. 1878. Bulletin de la Sociétéphilomathique de Paris (7th Séries) v. 2: 233-242. Diagnosis: Head dorso- ventrally flattened; rest of the body laterally compressed; pelvic fins with 8 rays; maxillaries and mandibulars short; maxillaries never reach base of pectoral or outermost part of opercle.

Fig. 5. Pangsinodon hypothalamus Fig. 6. Mystus oculatus Meristic counts: D- I, 7; P- I, i, 9; V- i, 7; A - iv, 29; C- 18. Metric characters: SL (mm)- 375.0; HL (mm) – 100.% SL:HL- 26.7; BDD- 40.0; BDA-34.7; BWD-18.7; BWA-13.3; PRD-37.9; POD-61.3; PRP- 22.9; PRPL-49.3; PRA-61.3; LAD- 5.6; LPL-12.3; LA-12.0; LBRD-7.2; LBA-29.1; LBP- 5.1; LBPL-5.9; LCP- 13.3; DCP-13.1; WCP- 6.1; DAV-1.1; DVV-9.8.% HL: HD- 65.0; HW- 58.0; ED- 10.0; IOW- 55.0; STL- 35.0; LMB- 32.0; LOMB- 19.0. Mystus oculatus (Valenciennes) Bagrus oculatus Valenciennes, 1839, IN Cuvier &Valenciennes Hist. Nat. Poiss. 14: 434 (type locality: ‘Cote de’(Kuttiadi), Malabar). Diagnosis: Occipital process extends to basal bone of dorsal fin; median longitudinal groove on head extends to base of occipital process; maxillary barbels extend to middle of anal fin; a dark spot is present at the origin of the dorsal fin. Meristic counts: D- I, 7; A- iii- iv, 8-9; P- I, 6; V- i, 5. Metric characters: TL (mm)- 10.2; SL (mm)- 7.8; HL (mm)- 18.0.% SL: BDD- 23.1; HL-23.1; HD-21.8; PRD-38.5; POD-64.1; PRP-50.0; PRA- 69.2; LD-24.4; LBRD-16.7; LBAD-14.1; LBA-12.8; LP- 19.2; LPL-15.4; DCP-10.3; LCP-10.3; LA-14.1; LAD- 12.8; LBPL- 3.8; LBP- 3.8. % HL: HD- 94.4; ED-16.7; IOW-41.7; STL-30.6. Other features: Silvery or yellowish on the flanks and darker on the dorsal region; abdomen whitish. Adipose dorsal fin base short; inter dorsal distance about 1.2 times in adipose dorsal fin base.



Mystus gulio (Hamilton- Buchanan) Pimelodus gulio Hamilton- Buchanan, 1822, Fish of Ganges: 201 (type locality: Upper parts of Gangetic Provinces). Diagnosis: Occipital process extends to the basal bone of dorsal fin; median longitudinal groove does not extend to the occipital process. Maxillary barbels extend to end of pelvic fins. Meristic counts: D- I, 7; P- I, 8-9; V- i, 5; A- iii- iv, 9-11; C - 17.

Fig. 7. Mystus gulio; Fig. 8. Mystus keralai Metric characters- TL (mm)- 156.0; SL (mm)- 125.0. % SL: HL- 27.6; HD- 17.8; HW- 21.8; BDD- 21.8; BDA-18.9; BWD- 19.9; BWA-11.1; PRD-36.8; POD-64.1; PRP-24.7; PRPL-52.2; PRA-67.2; LRD- 21.3; LP- 18.4; LPL- 12.7; LA- 16.0; LBSOD- 11.4; LBA- 11.0; LBP-5.1; LBPL- 4.0; LCP-15.7; DCP-11.1; WCP-5.3. . % HL: ED-15.55- 18.95; IOW-40- 43.90; INW--21.40- 24.77; STL-35- 39.63; WGM-36.58- 44.44. Other features: Body dark on the flanks and above; dull white below; fins black. Dorsal spine strong, serrated on its inner edge; adipose fin small, inserted considerably behind rayed dorsal fin; least height of caudal peduncle equals its length. Mystus keralai Plamoottil & Abraham Mystus keralai, Plamoottil& Abraham, 2014, Int.J. Pure Appl. Zool., 2 (3): 231- 240 (Type locality: Chenapady, Manimala River, Kerala). Diagnosis: Mystus keralai differs from its relative species in having an elongated, wider but less deep head, smaller eyes, deeper anterior part of frontal groove, longer adipose dorsal fin and pectoral spine, weaker pectoral spine and longer base of rayed dorsal fin base. Meristic counts: D- I, 7; P- I, 8; V-i, 5; A- iv, 9; C- 15. Metric characters: TL (mm)-72-78; SL (mm)- 58-59. % SL: HL-27.1- 27.6; HD-18.1- 18.9; HW-18.1- 18.9; BDD-21.0- 22.4; BDA-18.6- 18.9; BWD-15.8- 17.0; BWA-10.3- 11.2; PRD-36.2- 38.9; POD-67.2- 67.8; PRPL-48.3- 54.2; LRD- 22.4- 23.7; LC-29.8- 32.2. % HL: ED-21.9- 25.0; IOW-34.3- 34.4; INW-20.0- 25.0; STL-37.5; WGM- 37.5-45.0. Mystus heoki Plamoottil& Abraham Mystus heoki, Plamoottil& Abraham, Biosystematica, 2013: 7(1): 43-58 (Type locality: Elankadu, Idukki Dt, Kerala, India).



Fig. 9.Mystus heoki. Fig. 10. Mystus menoni Diagnosis: The new species can be differentiated from all its congeners in having a markedly elongated body, shorter head, smaller eyes, shorter rayed dorsal fin and shorter pectoral fin. Meristic counts: D- II, 7; P- I, 7; V- i, 5; A- ii- iii, 8; C-15. Metric characters: TL (mm) - 105.5- 167.0; SL (mm)-85.5- 137.0.% SL: HL-18.9- 22.5; HD-10.9- 12.5; HW-14.8- 17.4; BDD-15.0- 16.9; BDA-13.3- 16.4; BWD- 12.5- 15.2; PRD-31.7- 34.2; POD-59.7- 67.2; PRPL-43.3- 45.9; LRD-14.3- 15.4; LC-22.7- 24.5.% HL: ED- 16.7- 20.4; IOW-32.4- 38.6; STL- 36.4- 41.7; WGM- 41.7- 48.7. Mystus menoni Plamoottil & Abraham Mystus menoni Plamoottil & Abraham, Int. J. Pure Appl. Zool., 2013, 1(4): 315-325 (type locality: Elankadu, Manimala River, Kerala, India). Diagnosis: Mystus menoni can be diagnosed from all its congeners in having an elongated snout, widely set eyes, short inter dorsal distance and a thick bluish green band present in the mid lateral line. Meristic counts: D- II, 7; P- I, 7; V- I, 5; A- iii, 8; C- 15- 17. Metric characters: TL (mm)-128.5- 139.0; SL (mm)-101.0- 109.0.% SL: HL-22.9- 24.3; HD-13.9- 15.7; HW-17.8- 18.4; BDD-21.1- 23.6; BDA-16.8-18.8; BWD-17.3- 19.6; PRD- 33.0- 36.9; POD-59.8- 67.9; PRPL-46.3- 51.4; LRD-16.7- 20.8.% HL: ED-22.9- 25.0; IOW-36.0- 40.4; STL- 34.6- 41.7; WGM-42.3- 50.0 Mystus indicus Plamoottil & Abraham Mystus indicus, Plamoottil & Abraham, Biosystematica,2013: 7(1): 43-58 (type locality: Kuttoor, Manimala River, Kerala, India).

Fig. 11.Mystus indicus. Fig. 12.Mystus canarensis



Diagnosis: The new species can be differentiated from its congeners in having an elongated snout, a thick layer of flesh present on both sides of occipital process, pectoral spine with more teeth, greater pre pelvic length, rayed dorsal fin base prominently swollen on both sides and wide caudal peduncle. Meristic counts: D- I, 7; P- I, 6-8; V-i, 5; A- iii, 7-8; C- 15-17. Metric characters: TL (mm)-102.5-136.0; SL (mm)- 81.0-107.0.% SL: HL-22.4-26.0; HD-14.4-16.2; HW-16.7-20.2; BDD-18.8- 25.3; BDA-17.8- 21.2; BWD-16.7-19.2; PRD-30.8-36.0; POD-64.5-70.8; PRPL-50.6-55.5; LRD-15.8-21.8.% HL: ED-24.0- 29.2; IOW-36.3- 45.0; STL-36.2- 42.5; WGM-34.8- 40.9. Mystus canarensis (Grant) Mystus canarensis Grant, S. 1999, Aqua. J. Ichthyol.& Aquatic Biol, 3 (4): 169- 174. Diagnosis: A prominent dark brown spot present on the humeral region; length of base of adipose dorsal fin fairly short; caudal fin lobes overlap each other; pectoral fin with 9 branched rays and caudal fin with 18 rays. Meristic counts: D- I, 7; P- I, 9; V-i, 5; A- iii, 8; C-18. Metric characters: TL (mm)-107.0- 126.0; SL (mm)- 87.0-101.0.% SL: HL-22.8-24.3; HD-11.2-13.0; HW-15.0-17.8; BDD-17.2-20.8; BDA-16.6-18.1; BWD-14.7-16.8; PRD-36.2-38.1; POD- 62.0-65.8; PRPL-48.7-49.7; LRD-15.8-17.8.% HL: ED-20.4-27.5; IOW-30.2-35.0; STL-31.7- 36.3; WGM-39.0- 40.8. Ompok malabaricus (Valenciennes) Silurus malabaricus Valenciennes IN Cuvier &Valenciennes, 1839, Hist. Nat. Poiss. 14: 353 (type locality: Malabar). Diagnosis: Mouth somewhat oblique and its gape wide; maxillary barbels extend beyond pelvic fin origin; mandibular barbels extending posteriorly no farther than hind border of eye; pectoral spine strong, serrated on its inner edge. Meristic counts: D- I, 3; P- I, 11- 12; V- i, 7; A- iii, 63- 69. Metric characters: TL (mm)- 179.0; SL (mm)- 161.0. % SL: HL- 18.6; HD-14.3; HW-11.8; BDD- 19.8; BDA-19.2; BWD-13.0; BWA- 11.8; PRD-27.3; POD-59.6; PRP-20.5; PRPL-33.0; PRA-34.8; LP-11.2; LPL- 5.6; LA-11.2; LBP- 5.0; LBPL-2.5; LC- 11.2; DP-PL-15.0; DPL-A- 5.6; ED- 2.2; IOW-9.3; INW-6.2; STL-6.8; WGM-11.8.

Fig. 13.Ompok malabaricus Fig. 14.Ompok bimaculatus Other features: Teeth in broad villiform bands on jaws medially interrupted; teeth on vomer in two large, crescent- shaped patches, separated from each other by a distance equal to half length of one patch. Colour: Grayish brown shot with purple, which becomes paler yellow; the membrane of fin elements mottled with minute black dots. Ompok bimaculatus (Bloch) Silurus bimaculatus Bloch, 1797, Nat. Hist. Poiss. 17 (2) (type locality: Malabar).



Diagnosis: Lower border of eyes on the level of edge of mouth; anal fin not confluent with caudal fin; the latter is forked with round lobes; a black humeral blotch present. Meristic counts: D- 4; P- I, 9; V- I, 6; A- 64; C-14. Metric characters: TL (mm)- 119.0; SL (mm)- 105.0. % SL: HL- 22.4; HD-15.2; HW-12.4; BDD-20.2; BWD-9.5; PRD-36.2; POD- 68.6; PRP-21.4; PRPL- 30.5; PRA- 39.5; LP- 14.8; LPL-7.6; LA-7.1; LBP-4.8; LBPL-1.1; LC-13.3; DP- PL-11.0; DPL-A- 9.0; IOW-9.0; STL- 9.0; WGM- 1 1.2. Other features: Lateral line complete, extending from head to tail; various small grooves present on the ventral region of head. Maxillary barbels extend to the base of pectoral fin; a diffused black spot present on the lowest part of pectorals; pelvic fin extend to anal fin origin and a little longer; no space between anal and caudal fin. Wallago attu (Bloch & Schneider) Silurus attu Blotch &Scheiner, Syst. Ichthyol. 378 (type locality: Malabar). Diagnosis: Mouth is oblique and cleft of mouth extends beyond the orbit. Maxillaries extend well beyond origin of anal fin; pectoral spine weak, poorly serrated on its inner edge. Caudal fin deeply forked and its upper lobe longer.

Fig. 15.Wallago attu Fig. 16. Pseudotropius mitchelli

Meristic counts: D- 5; P- I, 13- 15; V-i, 7- 9; A-iii, 74- 93. Metric characters: TL- 303.0; SL- 270.0; HL- 5.9.% SL: HL-21.8; HD-14.1; HW-11.8; BDD-16.3; BDA-14.4; BWD-9.6; PRD-27.4; POD-68.5; PRP-20.4; PRPL-33.0; PRA-40.7; LD-14.8; LP-14.8; LPL-7.0; LA-3.0; LC-11.0; LBD-1.5; LBP-3.3; LBPL-2.6; LBA-57.4; LBC-4.4; LCP-1.8; DCP-4.4; WCP-1.1; DP- PL-14.1; DPL-A-7.4; DA- C-59.3; LUCL-12.2; LLCL-9.6; DO- ST-14.1; DO-D-16.0.% HL: HD- 64.4; HW-54.2; ED-11.8; IOW-44.1; INW-20.3; WGM-47.5. Pseudeutropius mitchelli Gunther Pseudeutropius mitchelli Gunther, 1864, Cat. Fish. Brit. Mus. 5: 59 (type locality: Madras presidency). Diagnosis: Maxillaries extend to middle of pelvic fin; adipose dorsal fin very small and located far back on the body; body height at dorsal origin 5.7- 6.2 in SL. Meristic counts: D- I, 6-7; P- I, 8-9; V- i, 5; A- 37; C- 16-18. Metric characters: TL (mm)- 125.0; SL (mm)- 106.0; HL (mm)- 20.0.% SL: HL-18.8; HD-12.3; HW-11.3; BDD-16.0; BDAD-11.3; BWD-11.3; BWAD-7.5; PRD-25.5; POD-72.6; PRP-18.8; PRPL-37.8; PRA-48.1; LRD-14.2; LAD-4.7; LP- 12.3; LPL-7.5; LA-9.4; LDSP-11.2; LPSP-10.4; LBRD-7.5; LBAD-0.9; LBP-2.8; LBPL- 2.8; LBA-35.0; DP-PL-17.9; DPL- A- 10.4; LCP-14.2; DCP-8.5; WCP-2.8; DRD & AD-44.3; LMB-38.7; LNB- 2.8; LOMB-18.8; LIMB- 18.8; LUCL- 18.8; LLCL-17.0.% HL: HD-65.0; HW-60.0; ED-30.0; IOW-40.0; INW-20.0; STL-35.0; WGM-30.0.



Glyptothorax elankadensis Plamoottil & Abraham Glyptothorax elankadensis, Plamoottil, M. & Abraham, N. P, 2012, Biosystematica, 6 (2): 17- 25 (type locality: Elankadu, Idukki dt, Kerala).

Fig. 17. Glyptothorax elankadensis Fig. 18. Heteropneustes fossilis

Diagnosis: A round yellowish spot in between eyes. Median fontanel on the dorsal side of the head very faint and indistinct. Occipital process does not reach basal bone of dorsal fin. Eyes very minute. Meristic counts: D- iii, 4-6; P- i, 8- 10; . V- i, 5; A- i-iii, 7-10; C- 17. Metric characters: TL (mm)- 124- 137; SL (mm)- 101- 115; HL (mm)- 25.0- 26.0.% SL: HL- 22.6- 24.7; HD- 13.0- 15.0; HW- 19.1- 21.8; BDD- 15.6- 18.2; BDA- 12.2- 16.3; BWD- 13.9- 18.8; BWA- 10.4- 13.8; PRD- 31.0- 36.4; POD- 54.4- 69.8; PRP- 19.5- 21.8; PRPL- 45.2- 49.5; PRA- 63.5- 67.4; LRD- 19.1- 21.8; LP- 20.9- 21.9; LPL- 17.3- 17.4; LA- 16.8- 17.4; LAD- 8.7- 16.4; LBRD- 10.4 -12.3; LBAD- 10.0- 15.4; LBA- 13.0- 13.6; LBP- 7.8- 9.1; LBPL- 4.3- 6.4; DRD & AD- 23.5- 40.0; LCP- 16.9- 19.8; DCP- 7.8- 8.2; WCP- 5.4- 6.4; DAV- 4.9- 5.5; DVV- 11.3- 13.6. % HL: HD-57.7- 63.5; HW- 84.6- 88.5; ED- 4.0- 7.7; STL- 50.0- 54.0; IOW- 23.8- 30.8; INW- 16- 2.1; WGM- 36.0- 42.3; LMB- 84.8- 96.2; LBMB- 15.4- 23.1; LNB- 15.4- 26.9; LOMB- 38.0- 46.2; LIMB- 23.1- 26.9; LATA- 57.7- 60.0; WATA- 38.5- 44.0. Heteropneustes fossilis (Bloch) Silurus fossilis, Bloch, 1794, Naturg.Ausland Fische 8; 46 (type locality: Tranquebar). Diagnosis: Median frontal groove on head limited to a round depression between and backwards of eyes; occipital process short and not extending to base of dorsal fin; rayed dorsal fin is short and without a spine; anal fin long based, separated by a distinct notch from caudal fin. Meristic counts: D- 6-7; P- I, 7; V- i, 5; A- 60- 70. Metric characters: TL (mm) - 171.0; SL (mm) - 150.0; HL (mm)- 29.0. % SL: HL- 19.3; HD-10.0; HW-16.0; BDD-20.0; BWD-15.3; PRD-32.7; POD-68.7; PRP-16.7; POD-68.7; PRP-16.7; PRPL-35.3; PRA-40.7; LD-11.3; LP-13.3; LPL-8.7; LA-10.7; LC-14.0; LBD-40.0; LBP- 26.7; LBPL-18.0; LBA- 48.7; LBC-40.0; DP-PL-21.3; DPL-A-40.0. % HL:ED-13.8; IOW-48.3; INW-27.6; WGM-38.0; DO-ST-82.8; DO-D-86.2. Other features: Body yellow above and on lateral sides, lighter below; dorsal located a little in front of pelvic; pectoral never reach pelvic fin, the latter reach behind anal origin; anal never fused to caudal Clarias dussumieri Valenciennes Clarias dussumieri Valenciennes IN Cuvier &Valenciennes Hist. Nat. Poiss, 1840, 15: 382 (type locality: Pondicherry and Malabar).



Diagnosis: Head depressed snout broad; occipital process broadly rounded; anal and dorsal fins are long based. Pectoral fin with a strong spine, which is serrated on its outer edge, but only a few small teeth present in the middle of its inner margin. Meristic counts: D- 66- 69; P- I, 10- 14; V- I, 5; A- 45- 59. Metric characters: TL (mm)- 270.0; SL (mm)- 235.0.% SL: BDD-15.3; HL-24.2; HD- 12.0; PRD-36.2; POD-77.4; PRP 49.0; LD-4.3; LBAD-60.0; LBA-30.6; LP-12.3; LPL-10.2; LCP-4.7; DCP-7.2. Other features: Body color dark above, lighter ventrally; dorsal, anal and caudal fins are tinged with red. Clarias gariepinus (Burchell) Diagnosis: Cephalic groove divided into two fontanels; of this, anterior one is elongated and posterior one is round and deep; in addition to this a small groove present on occiput also; occipital process never reach dorsal fin front; nasal barbels short and never reach occiput; maxillaries and outer mandibulars reach just behind pectoral base, inner mandibulars never reach pectoral base. Tip of pelvic fin reach behind the origin of anal fin. Dorsal and anal fin long but never fused to caudal. Meristic counts: D- 63; P- I, 8; V- 6; A- 52; C- 19.

Fig. 19. Clarius gariepinus Fig. 20. Arius subrostratus Metric characters: TL (mm)- 352.0; SL (mm)- 307.0; HL (mm)- 66.0.% SL; HL- 21.5; HD-11.4; HW-18.6; BDD-14.0; PRD-30.5; POD-63.5; LD-3.3; LBA-44.0; LP-10.7; LPL-11.1; LA-5.2; LC-14.6; DP- PL- 22.1; DPL- A- 9.4; DAV- 3.3; DVV- 4.6.% HL: HD-53.0; HW-86.4; ED-10.6; STL-37.8; IOW-48.5; INW-34.8; LMB-92.4; LNB-47.0; LOMB-74.2; LIMB-55.3. Arius subrostratus Valenciennes Arius subrostratus Valenciennes, Hist. nat. Poiss., 15, P.62 (Type locality: Malabar) Diagnosis: Cephalic frontal groove narrow, considerably deep and reach to occiput; occipital process reaches dorsal front; distal half of last undivided ray of rayed dorsal fin extremely long, filamentous and extends up to or very near to origin of adipose dorsal fin; anal tip reach caudal base. Meristic counts: D- I, 7; V- i, 6; P- I, 12; A- VI, 14; C- 16. Metric characters: TL (mm)- 252.0; SL (mm)- 216.0.% SL; HL- 20..5; HD-1.1; HW-16,2; BDD-12.0; PRD-28.5; POD-60.5; LD- 6.7; LBA-41.0; LP-11.7; LPL-10.0; LA-4.2; LC-13.6; DP- PL- 20.1; DPL- A- 7.4.% HL: HD-59.2; HW- 65.3; ED-22.4; STL-44.8; IOW-34.7; INW-14.3. Other features: Upper caudal lobe longer than the lower one; dorsal spine serrated on inner and outer sides; pectoral spine finely serrated on outer side and moderately serrated on inner side. Maxillary barbels reach just behind the



front border of orbit and also reach half way between maxillary base and pectoral base; outer mandibulars shorter than maxillary; it never reach orbit; inner mandibulars shorter than outer mandibulars; no nasals.

CONCLUSION

Even though many scientific studies are being conducted on the freshwater fishes of central Travancore, detailed taxonomic studies are very rare. Ichthyodiversity was found to be greater in this region; moreover, some species are abundantly distributed in the low level regions. But total number of many species has greatly been reduced; many fishes were not collected from some sites from where they were recorded in the past. Aquatic bioinvasion and habitat destruction are major reasons for the decline of biodiversity of fishes. Acknowledgement The author acknowledges Principal, Baby John Memorial Government College, Chavara, Kerala for providing the

facilities. I am grateful to anonymous reviewers for comments that helped to improve the manuscript.

REFERENCES

[1] Bornbush, A. H. Zool. J. Limn. Soc.1991,101: 105- 120. [2] Ferraris, C. J. Pinna, M. C. C. de.Proc. Calif. Acad. Sci. 1999, 51 (1): 1- 17. [3] Ferraris, C. L. Zootaxa, 2007, 1418: 441. [4] Mo, T. Anatomy and Systematics of Bagridae (Teleostei) and siluroid phylogeny. Koeltz, scientific books, Koenigstein, Germany, 1991, 125. [5] de Pinna, M.C.C. Higher level phylogeny of Siluriformes (Teleostei, Ostariophysi) with a new classification of the order. Ph.D dissertation.City University of New York.American Museum of Natural History, 1993. [6]de Pinna, M. C. C.Fieldiana Zoology New Series, 1996, 84: iv+ 83. [7] Misra, K. S. The fauna of India and Adjacent countries.Siluri, Zoological Survey of India, Kolkata,1976, 3:109. [8] Jayaram, K. C. Sanyal, A. A taxonomic revision of the fishes of the genus MystusScopeli.Records of Zoological Survey of India, Occational Paper No. 207,2003, 136. [9] Jayaram, K. C. Cat fishes of India, Narendra Publishing House, Delhi,2006, 41- 145.

taxonomic notes on catfishes of travancore...jzbr copy

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