676Indian Journal of Geo-Marine Sciences INDIAN J MAR SCI VOL 43(4), APRIL 2014 Vol. 43(4), April 2014, pp. 676-698 Crab biodiversity from Arukkattuthurai to Pasipattinam, south east coast of India D. Varadharajan & P. Soundarapandian Faculty of Marine Sciences, Centre of Advanced Study in Marine Biology, Annamalai University, Parangipettai-608 502, Tamil Nadu, India. [E-Mail: [email protected]] Received 30 July 2012; revised 14 January 2013 Coastal environment provides a greater range of habitats and thus potentially supports greater biodiversity. Before starting to produce seeds in a hatchery and culture them in ponds, thorough knowledge about their distribution in nature is important. So the present study is aimed to know the biodiversity of crabs from Arukkattuthurai to Pasipattinam. Totally 79 individual crab species were recorded belonging to 21 families from all 10 stations. Maximum crab species were recorded belonging to the family Portunidae than others families and also the maximum number of crab species 163 were recorded in Mallipattinam (station5) and minimum 69 species in Pasipattinam (station10). Occurrence of crab species in different stations were in the following order; Mallipattinam (163) > Sethubavachatram (161) > Manamelkudi (127) > Pointcalimere (117) > Muthupettai (116) > Jegathapattinam (110) > Kattumavadi (101) > Arukkattuthurai (92) > Adirampattinam (85) > Pasipattinam (69). Crabs were collected plenty during summer and monsoon than pre-monsoon and post-monsoon. The crabs belonging to families viz., Calappidae, Portunidae, Potamidae, Grapsidae, Sesarmidae and Ocypodidae were obtained almost all seasons. [Keywords: Crabs, Family, Portunidae, Distribution, Abundance] Introduction introduction are identified as main threat to 9 Biodiversity is important for human survival and biodiversity . India, a mega biodiversity country, economic interests and for the environmental purpose definitely needs conservation strategy to save the and stability. India’s marine and coastal ecosystems biodiversity. Although, the crabs are caught constitute an important natural resource, since throughout the year at various regions of the coast, millions of people dependent on them for their the main season varies from place to place10. In the livelihoods. This rich biodiversity has a significant present study an attempt has been made on the role in the maintenance of the ecosystem. Crustaceans biodiversity of crabs from Arukkattuthurai to are visibly a remarkable group of organisms with a Pasipattinam south east coast of India. long evolutionary history and prominent adaptability. Materials and Methods The decapod crabs are mostly active animals with complex behaviour patterns. Southern coast of Tamil The present study was carried out for one year Nadu has a very narrow continental shelf, with high from January 2010 to December 2010 from salinity, a rocky shore and strong wave action. It Arukkattuthurai to Pasipattinam, south east coast of includes mangroves, sandy beaches, mudflats, coral India. Ten different stations were selected for the reefs and seagrass beds1,2. Detailed study on decapod present study viz., Arukkattuthurai (Station1), crab fauna was already made in Indian seas by Pointcalimere (or) Kodikkarai (Station2), Muthupettai different workers3,4,5,6,7,8. Habitat destruction, (Station3), Adirampattinam (Station4), Mallipattinam pollution, over exploitation and new species (Station5), Sethubavachatram (Station6), VARADHARAJAN & DARAPANDIAN: CRAB BIODIVERSITY FROM ARUKKATTUTHURAI TO PASIPATTINAM 677 Kattumavadi (Station7), Manamelkudi (Station8), Jegathapattinam (Station9) and Pasipattinam (Station10). Crabs were collected by using FRB boats in different depths (up to 25 m) and 40–50 mm net was used (Length 80–100 m, Breadth 1.0-1.5 m). Apart from collection a regular visit was made in different fishing sites, landing centres and sell points. The number of crabs that belonging to different species were recorded and identified up to species level using the taxonomic keys of 11,12,13,14. Results In the present study totally 79 crab species were recorded belonging to 21 families. Family Aethridae was represented by single genera consists (Cryptopodia) of a species C. fornicata. Family Calappidae was represented by 2 genera (Calappa and Matuta) consists of 4 species which includes C. lophos (Plate1a1), C. gallus (Plate1a2), M. lunaris (Plate1a3) and M. planipes (Plate1a4). Family Carpillidae was represented by a genera (Carpilius) consists of a species C. maculates (Plate1a5). Family Dorippidae was represented by 3 genera (Dorippoides, Dorippe and Ethusa) consists of 3 species which includes D. facchino (Plate1a6), D. quadridens (Plate1a7) and E. indica. The family Leucosiidae was represented by two genera (Oreophorus and Arcania) consists of 2 species which includes O. reticulates and A. septemspinosa (Plate1a8). The family Hymenosomatidae was represented by only one genera (Elamena) consists of a species E. cristatipes. Family Majidae was represented by 3 genera (Hyastenus, Doclea and Achaeus) consists of 3 species which includes H. gracilirostris, D. gracilipes and A. lacertosus. The family Parthenopidae was represented by 2 genera (Parthenope and Platylambrus) consists of 2 species which includes P. echinatus and P. prensor. The family Pilumnidae was represented by only one genera 678 INDIAN J MAR SCI VOL 43(4), APRIL 2014 (Pilumnopeus) consists of a species P. vespertilio The family Xanthidae was represented by 4 genera (Plate1a9). Family Portunidae was represented by 5 (Paractaea, Leptodius, Zozymodes and Demania) genera (Scylla, Portunus, Podophthalmus, Charybdis consists of 4 species which includes P. neospeciosa, and Thalamita) consists of 24 species which includes L. exaratus, Z. cavipes and D. buccalipes. The family Scylla tranquebarica (Plate1a10), S.serrata (Plate1a11), Oziidae was represented by only one genera (Ozius) Portunus sanguinolentus (Plate1a12), P. pelagicus consists of a species O. rugulosus. The family (Plate1a13), P.gladiator (Plate1a14), P. hastatoides Grapsidae was represented by 7 genera (Grapsus, (Plate1a15), P.trituberculatus (Plate1a16), Metopograpsus, Metaplax, Leucosia, Philyra, Dromia and Plagusia) consists of 9 species which includes Podophthalmus vigil (Plate1a17), C.affinis (Plate1a18), Grapsus albolineatus, G. strigosus, M. messor, C.feriata (Plate1a19), C.natator (Plate1a20), M. maculatus, M. distincta, L. pubescens, P. globosa, C. (Goniosoma) lucifera (Plate1a21), C. (Goniohellenus) D. dormia and P. depressa tuberculata. The family truncata (Plate1a22), C. hellerii (Plate1a23), Sesarmidae represented by 2 genera (Sesarma and C. granulata (Plate1a24), C. rostrata, C. japonica, C. miles, C. variegata, C.hoplites, T. picta ,T. chaptali, Nanosesarma) consists of 5 species which includes T. crenata and T. sima. The family Potamidae was S.brockii, S. (Chiromantes) bidens, S. (Parasesarma) represented by 3 genera (Sartoriana, Spiralotelphusa plicatum, S. tetragonum and N. batavicum. Family and Potamon) consists of 3 species which includes Ocypodiae was represented by 3 genera (Uca, S. spinigera, S. hyhrodroma and P. fluviatile. The Ocypoda and Dotilla) consists of 6 species which family Trapeziidae was represented by only one includes U. annulipes, U.lactea, U.vocans, genera (Trapezia) consists of a species of T. cymodoce. O. platytarsis, O. macrocera and D.myctiroides. Family Macrophthalmidae was represented by only one genera (Macrophthalmus) consists of 2 species which includes M. convexus and M. depressus. The family Gecarcinidae was represented by only one genera (Cardisoma) consists of a species C. carnifex. Family Diogenidae was represented by 2 genera (Clibanarius and Dardanus) consists of 4 species which includes C. longitarsus, C. arethusa, C. olivaceus and D. megistos. Family Paguridae was represented by only one genera (Spiropagurus) consist of a species S. spirifer (Table 1). Maximum crab species recorded in the present study was belonging to the family Portunidae than others families and also the maximum 79 species were recorded in Mallipattinam (station5) and minimum 42 species in Pasipattinam (station10). The occurrence of crab species in different stations were in the following order; Mallipattinam (163) > Sethubavachatram (161) > Manamelkudi (127) > Pointcalimere (117) > Muthupettai (116) > Jegathapattinam (110) > Kattumavadi (101)> Arukkattuthurai (92) > Adirampattinam (85)> Pasipattinam (69) (Table 1). In the present study maximum crabs were collected during summer and monsoon than pre-monsoon and post-monsoon. The VARADHARAJAN & DARAPANDIAN: CRAB BIODIVERSITY FROM ARUKKATTUTHURAI TO PASIPATTINAM 679 Table 1—Checklist of crab species recorded during the study in different stations S. No Species Stations & (No/m2) Family 12345678910 1 Cryptopodia fornicate (Fabricius, 1781) Aethridae ++++++++++ 2 Calappa lophos (Herbst, 1782) Calappidae ++++++++++ 3 C. gallus (Herbst, 1803) ++++++++++ 4 Matuta lunaris (Forskal, 1775) ++++++++++ 5 M.planipes (Fabricius, 1798) + + * +++++** 6 Carpilius maculatus (Linnaeus, 1758) Carpillidae ++++++++++ 7 Dorippoides facchino (Herbst, 1785) Dorippidae ++++++++++ 8 Dorippe quadridens (Fabricius, 1793) ++++++++++ 9 Ethusa indica (Alcock,1894) * + * * + + * + * * 10 Oreophorus reticulatus (Adams & White, 1849 ) Leucosiidae * + * * + + * + * * 11 Arcania septemspinosa (Fabricius, 1787) ++++++++++ 12 Elamena cristatipes (Gravely, 1927) Hymenosoma-tidae ++++++++++ 13 Hyastenus gracilirostris (Miers, 1879) Majidae ++++++++++ 14 Doclea