Introduction

Ocypode, called the ghost crab, is a large genus witha worldwide distribution in all oceans from the tropicaland subtropical coasts, from the American Atlantic,through the Mediterranean and Red Sea, to the AmericanPacific and Indo-Pacific region. The 3 species, namelyOcypode kuhlii de Hann, 1835 recorded from a sandspit,another species Ocypode ceratophtalma (Pallas, 1772)recorded from Dongi Island and Ocypode rotundata(Ortmann, 1898) from Dongi and Manora Island, werefirst recorded by Hashmi (1962, 1963, 1968) andTirmizi and Kazmi (1986), respectively. After this noattention has been paid to this genus and no noticeablework has been done on them. The specimens are housedin the repository of the Museum of the Department ofZoology, University of Karachi.

Materials and Methods

The material on which the present study was basedwas collected from Sonmiani beach on the Makran coast.Collecting was performed from April to September 2003,at low tide once a month. Crabs were preserved bynarcotizing them in chloroform and then preserving themin 6% formalin. Keys given by Faxon (1895), Alcock(1900), Chappgar (1956), Vannini and Valmori (1981)and Cannicci et al. (1993) were followed for species inthe present collection.

Systematics

Ocypode (Weber, 1795)

Carapace squarish; folded longitudinally. Eye-stalkslarge, moderately stout, cornea large covering much oflower surface of eyestalk usually subterminal andreaching toward base of eyestalk. No flagellum onexopodite of outer maxilliped. Chelipeds well developed,unequal but noticeably different on either side or in eithersex. The dactylus is fairly long, straight, pointed or blunt,it bears a longitudinal sulcus, dactylus is also importanttaxonomically.

Key to Species of the Pakistani Ocypode

1- Carapace squarish, greatest breadth about a tenthmore than its greatest length.…………....……..2

- Carapace is less distinctly quadrilateralanterolateral borders are arched. ……......….… 3

2- Protopodites of first 2 pairs of pereiopods haveconspicuous brush of hairs ………………..(Figures1a-c, 2a-e). O. ceratophthalma

- Thick brush of hair along the anterior surface ofprotopodite of the first pairs of pereiopods only………………………..................………….….4

3- Chelipeds stout, somewhat unequal, rough finger withtruncate ends...(Figures 3a-d, 4a-d). O. gaudichaudii.

Turk J Zool31 (2007) 107-112© TÜB‹TAK

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Some Ghost Crabs of the Genus Ocypode (Decapoda: Brachyura:Ocypodidae) from Pakistan’s Waters (Northern Arabian Sea)

Farzana YOUSUF1, Farah ALI1, Quddusi B. KAZMI2

1Department of Zoology, University of Karachi, Karachi-75270- PAKISTAN

2Marine Reference Collection and Resource Centre, University of Karachi, Karachi – 75270 - PAKISTAN

Received: 12.04.2005

Abstract: The present paper is based on the ghost crabs Ocypode ceratophthalma, O. gaudichaudii, O. macleayana, and O. rotundata,belonging to the Brachyuran genus Ocypode. The specimens were collected from the sandy beach of Sonmiani on the Makran coast.Four species belonging to 1 genus are described in detail and illustrated.

Key Words: Decapoda, Ocypode crabs, Ocypodidae, Pakistan

- Chelipeds smooth, fingers, finelytoothed....…(Figures 5a-e , 6a-d). O. macleayana..

4- Dactyli of the pereiopods are dorso-ventrallycompressed …… (Figures 7a-e, 8a-d). O. rotundata.

Results

Ocypode ceratophthalma (Pallas, 1772) (Figures 1a-c, 2a-f).

Cancer ceratophthalmus Pallas, specilegia Zool. IX.P.83,

PL.V. Figs. 7. 8; Cancer Cursor, Herbst, Krabhen,I.li.74, pl.i. Figs.8, 9. Ocypoda ceratophthalma Fabricius,Ent. Syst. Suppl. P.347: Milne Edwards, Hist. Nat. Crust.11 48, and Cuvier Reque An. Crust. Pl.17; Kingsley,proc, Ac. Nat. Sci. Philad,1888, p.179; Miers, Ann. Mag.Nat. Hist (5) X, 1882, pp. 378, 379: C.W.S, Aurivillius,

Zur, Biol, Amphib. Decap., p. 17 (Mitg.K.Ges. Wiss.Upsala, 1893); Ortmann, Zool. Jahrb, Syst. X. 1898:360, 364 (ubi synon).

Material: 1 Adult Female, Locality: Sonmiani, MakranCoast, Carapace length: 67 mm. Carapace width: 59 mm.

Description: Carapace (Figure 1a) squarish, broaderthan long, anterior corners flattened; front between theeyes narrow, bent down. Eyestalks large, elongated,prolonged beyond the cornea in a slender style.Antennules attached below the eyes (Figure 1b). Eachantennule consists of a 3-segmented peduncle, thecoxopodite and a 2-segmented basiopodite. Distalsegment of basiopodite bears whip-like flagella. Thirdmaxilliped pediform, basis large and distinct with ischiumby a line and then distinct into merus, carpus, propodusand then dactylus. All segments fringed with setae.Exopodite long, slender and unsegmented. Granulespresent on third maxilliped, which have taxonomicimportance (Figure 1c). Abdomen (Figure 2a) somewhatslender, broad with 6 somites. Chelipeds stout (Figure2b, 2c) somewhat unequal, rough; fingers with truncateends. Ambulatory pereiopods third and fourth (Figure 2d,2e) long finely roughened. Gonopod of female (Figure 2f)slender.

These species are widely distributed from California toChile and in the Arabian Sea near Sonmiani, Makrancoast, Pakistan, especially on sandy beaches.

Ocypode gaudichaudii H. Milne Edwards and Lucas,1843 (Figures 3a-d, 4a-d).

Milne Edwards and Lucas. in D’Orbigny’s Voy. DansAmer. Mer., 6, pt.1, p. 26, 1843, pl. 11, figs. 4-4b,1847; Rathbun, II. A. E., 10, 190,1904; Proc. U.S. Nat.Mus., 38, 550, pl. 43, fig. 2, 1918; Bull. U.S. Nat. Mus.,97, 373, pl. 63.

Material: Two individual adult males were obtained.Locality: Sonmiani, Makran coast, Carapace length: 64mm. Carapace width: 56-64 mm.

Description: Carapace (Figure 3a) same as that in O.ceratophthalmus, squarish, broader than long.Antennules as illustrated in Figure 3b. Chelipeds stout(Figure 3c, 3d, 3e) somewhat unequal, rough; fingerswith truncate ends. Ambulatory pereiopods (Figure 4b,4c) long finely roughened. Abdomen (Figure 4a)somewhat slender and elongated with 6 somites.Gonopod of male (Figure 4d) also slender.

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a

b

c

b c

1 m

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0.25

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Figure 1. Ocypode ceratophthalma. Adult female, a, dorsal view; b,antennule; c, third maxilliped.

Distribution, same as that of Ocypodeceratophthalmus, from California down to Chile and inthe Arabian Sea near Sonmiani, Makran coast, Pakistan,especially on sandy beaches.

Ocypode macleayana Hess, 1865 (Figures 5a-e, 6a-d).

Hess, Archiv fur Naturg, Band XXXI.P. 143, pl .vi,fig.8 1865.

Material: One adult male. Locality: Sonmiani, Makrancoast, Carapace length: 67 mm. Carapace width: 67 mm.

Description: Carapace (Figure 5a) broader than long,anterolateral border has short granular ridges andconsiderably serrated margins. One eye’s styliformsmaller than other. Upper orbital border slightly curved,

almost straight. Cornea at the end of peduncle overhungby a process of the latter (Figures 5a, 5b). Thirdmaxilliped as illustrated in Figure 5c, granules on thebasis and ischium. Chelipeds (Figure 5d) shorter thanpereiopod and remarkably unequal, larger one beingmuch greater in size, dactylii of 4 posterior pereiopods(Figures 4a, 4b) very long; pereiopods with dark bands.Anterior second and third pereiopods (Figures 6b, 6c)very small, Abdomen (Figure 6a) spatulate, granules arepresent on all segments, each joint of the abdomen with2 red spots. Gonopod described and illustrated in Figure6d. Widely distributed in the Indo-Pacific, especially alsofound on sandy beaches.

F. YOUSUF, F. ALI, Q. B. KAZMI

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a

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f

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d

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e

Figure 2. Ocypode ceratophthalma. Adult female, a, abdomen dorsalview; b, first pereiopod or chela. (left side); c, first pereiopodor chela. (right side); d, second pereiopod; e, thirdpereiopod; f, gonopod.

bcd

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d

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Figure 3. Ocypode gaudichaudii. Adult male: a, dorsal view; b,antennule; c, first pereiopod or chela (left side); d, firstpereiopod or chela (right side).

Ocypode roduntada (Miers, 1882) (Figures 7a-e, 8a-d).

Ortmann, 1898; Ocypode rotundata Miers, Ann.Mag. Nat. Hist (5)

X.1882; 378, Ann. Zool. Jahrb Syst., 1898: 360-364.

Material: 3 individuals were obtained: 2 adult males,Locality; Sonmiani, Makran coast, Carapace length: 58-67mm; Carapace width: 48-67 mm. 1 adult female,Carapace length: 60-67 mm.

Description: Carapace (Figure 7a) less distinctlyquadrilateral, antero-lateral borders and arched, insteadof forming an angle with upper border of the orbit.Eyestalks have a long styliform straight process missing

in juveniles. Antennules as illustrated in Figure 7b. Thirdmaxilliped pediform and as illustrated in Figure 7c. Allsegments including merus, carpus, propodus and dactylusfringed with setae, granules scattered. Fingers of smallercheliped (Figures 7d-7e) almost as much dilated at the tipas those concealed in hairs, and each ridge sharplyserrated. Scraper on ischium placed near upper angle ofinner face of joint. First and second pereiopods (Figures7d, 7e) of males have a double brush of hair on lowerface of propodus. Meropodites of second and third pairsof pereiopods not so broad (Figures 8b, 8c). In female asingle brush of hairs on first and barely visible on secondpereiopod. Abdomen (Figure 8a) with 6 segments.Gonopods paired situated on coxae of fifth pereiopods asillustrated in Figure 8d. Distribution in the Indo-Pacificand Persian Gulf. Found on sandy beaches.

Some Ghost Crabs of the Genus Ocypode (Decapoda: Brachyura: Ocypodidae) from Pakistan’s Waters (Northern Arabian Sea)

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a

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ad

Figure 4. Ocypode gaudichaudii. Adult male: a, abdomen dorsal view;b, second pereiopod; c, third pereiopod; d, gonopod.

0.1

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Figure 5. Ocypode mecleayana. Adult male: a, dorsal view; b,antennule; c, third maxilliped; d, first pereiopod or chela (leftside); e, first pereiopod or chela (right side).

Discussion

Four specimens of the genus Ocypode were collectedfrom Sonmiani beach 25º23' N 066º33' E on 22February 2003 and during a second trip on 17September 2003 at low tide.

Ocypode rotundata differs from Ocypodecerratophthalma in having rounded antero-lateral anglesof the carapace. The spines or serrations at the innerangle of the wrist are more numerous and at the outerangle are better marked. The meropodites of the first 3pairs of pereiopod are not as broad as in other species ofOcypode. The length of the stridulating organ is much lessthan half the greatest height of the palm.

Ocypode ceratophthalma differs by havingpronounced anterolateral angles of the carapace. Themerus and ischium of the external maxillipeds have theirexposed surface circumscribed by a raised row of

granules. The length of the stridulating organ of the largepalm is greater in length, and it is more than the greatestbreath of the palm. The first 3 pairs of pereiopods havebroadened merus.

Ocypode gaudichaudii differs by having flattenedanterior corners of the carapace, and stout, roughchelipeds. Fingers have truncate ends. Its ambulatorypereiopods are long and finally roughened.

Ocypode macleayana differs by having upper orbitalbroader slightly curved, almost straight. Cornea at theend of the peduncle is overhung by a process of the latter.Dactyli of the 4 posterior pereiopods are very long. Thethorax is darker and spotted. It is identified by each jointof the abdomen having 2 red spots. The pereiopods havedarker bands. The present study is based on 4 species ofOcypode; this study will be useful in determining thetaxonomic status of the species.

F. YOUSUF, F. ALI, Q. B. KAZMI

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Figure 6. Ocypode macleayana. Adult male: a, abdomen dorsal view; b,second pereiopod; c, third pereiopod; d, gonopod.

bcde

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Figure 7. Ocypode roduntada. Adult male: a, dorsal view; b, antennule;c, third maxilliped; d, first pereiopod or chela (left side); e,first pereiopod or chela (right side).

Acknowledgments

We are grateful especially to Maria de Claderom fromSmithsonian Environmental Research Centre, USA, forsending us literature not available and for her readinessto help. Our thanks go to Dr. Shane T. Ahyoung,Department of Marine Invertebrates, Sydney, Australia,for support in preparing this work. We are indebted toProf. Dr. Gustavo Augusto S. de Melo, Universidade deSao Paulo, Sp. for making valuable suggestions. Also, ourdeepest gratitude goes to Dr. Javed Mustaqeem,Professor of Centre of Marine Excellence, University ofKarachi, for giving help and guidance in making drawings,offering criticism and giving valuable suggestions.

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Chappgar, B.F. 1956. On the marine crabs (Decapoda: Brachyura) ofBombay state part I. Journal of Bombay Natural History ofSociety. 54: 399-439.

Faxon, W. 1895. Reports on an exploration of the west coast of Mexico,Power station and South America, and the Galapagos Islands bythe U.S. Fish Commission Steamer “Albatross” during 1891. XV.The stalk eyed Crustacea. Mem. Mus. Comp. Zool, Harvard, 18:1-292.

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Hashmi, S.S. 1968. Study on larvae of (Gelasimus) (Ocypodidae) rearedin the laboratory (Decapoda: Crustacea). Pakistan Journal ofScientific Research 20: 50-56.

Hess, W. 1865. Beiträge zur Kenntniss der Decapoden-Krebse Ost-Australiens. Archiv fur Naturgescicthe. 31: 127-173 pls 6-7.

Kingsley, J.S. 1880. Carcinological notes, III - Revision of the genusOcypoda. Proceedings of the Academy of Natural Sciences ofPhiladelphia, 179-186.

Milne Edwards, H. and Lucas, H. 1843. Crustacés. Pp. 1-39 in Voyagedans l'Amerique Meridionale (Le Brésil, la République crientale del'Urugauy, la République Argentine, la Patagonie, la Républiquedu Chili, la République de Bolivia, la République du Pérou),exécuté pendant les années 1826, 1827, 1828, 1829, 1830,1831, 1832 et 1833, A. D. d'Orbigny, ed., Volume VI, Part I +Atlas. Paris: Bertranad.

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Rathbun, M.J. 1904. Decapod crustaceans of the northwest coast ofNorth America. In Crustaceans, Harriman Alaska Expedition, 10:3-211. Reprinted Publs Smithsonian Institution, (1997): 1-337.

Rathbun, M.J. 1918. The grapsoid crabs of America. United StatesNational Museum Bulletin 97: 1-461.

Tirmizi, N.M. and Kazmi, Q.B. 1986. Marine Fauna of Pakistan: 4.Brachyura (Dromiacea, Archaeobrachyura, Oxystomata,Oxyrhyncha). 244 p., 65 figs, 4 (2 col.) pls.

Vannini, M. and Valmori, P. 1981. Researches on the coast of Somalia.The shore and the dune of Sar Uanle. 30. Ocypodidae andGecarcinidae (Decapoda Brachyura). Monitore Zoology. Italiano.NS (Suppl.) 14: 199-226.

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Figure 8. Ocypode roduntada. Adult male: a, abdomen dorsal view; b,second pereiopod; c, third pereiopod, d, gonopod.