Abstract
A new species of potamid crab of the genus Badistemon Yeo & Ng, 2007, is described from Kamjong district of Manipur, India. Badistemon fulvum n. sp., can be distinguished from congeners by a distinct combination of carapace and gonopod characters: carapace subquadrate, convex, dorsal surface glabrous, cervical groove superficial, anterolateral margin longer than posterolateral margin; cornea relatively large; sixth male pleonal somite trapezoidal in shape, male telson broader than long; terminal segment of male first gonopod relatively long, outwardly bent, sub cylindrical with low and short dorsal flap, tip pointed, groove for male second gonopod terminal. Holotype and paratypes of Potamiscus pealianus (Wood-mason, 1871) are re-examined, and the species is here referred to Badistemon as carapace morphology and male gonopods characters are found congeneric with the genus. A key for all the three species of Badistemon are provided.
References
Alcock, A. (1909) Diagnoses of new species and varieties of freshwater crabs. No.13. Records of the Indian Museum, 3 (3), 243–252.
Alcock, A. (1910) The Indian Freshwater Crabs–Potamonidae, Catalogue of the Indian Decapod Crustacea in the collection of the Indian Museum.Part 1.Brachyura. Fasc. II. Trustees of the Indian Museum, Calcutta, 135 pp., 14 pls.
Brandis, D. (2000) The taxonomical status of the freshwater crab genus PotamiscusAlcock 1909 (Decapoda, Brachyura, Potamidae). Senckenbergiana biologica, 80, 57–100.
Bott, R. (1970) Die Süßwasserkrabben von Europa, Asien, Australien und ihre Stammesgeschichte. Eine Revision der Potamoidea und Parathelphusoidea (Crustacea, Decapoda). Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft, Frankfurt, 526, 1–338, pl. 1–58.
Davie, P.J.F., Guinot, D. & Ng, P.K.L. (2015) Anatomy and functional morphology of Brachyura. In: Castro, P., Davie, P.J.F., Guinot, D., Schram, F.R. & Von Vaupel Klein, J.C. (Eds.), Treatise on Zoology—Anatomy, Taxonomy, Biology. The Crustacea, Part 1 (Decapoda: Brachyura), 9C–I, pp. 11–163.
https://doi.org/10.1163/9789004190832_004
Mitra, S. (2017) Freshwater crab (Crustacea: Decapoda: Gecarcinucidae & Potamidae) of Mizoram. Records of the Zoological Survey of India. Occasional Paper, 382, 1–43, pls. 1–32.
Mitra, S. & Waikhom, M.D. (2019) A new species of freshwater crab of the genus Potamiscus Alcock, 1909 (Crustacea: Brachyura: Potamidae: Potamiscinae) from Manipur, north-eastern India. Journal of Emerging Technologies and Innovative Research, 6, 624–634.
Naruse, T., Chia, J.E. & Zhou, X. (2018) Biodiversity surveys reveal eight new species of freshwater crabs (Decapoda: Brachyura: Potamidae) from Yunnan Province, China. Peer J, 6, e5497.
https://doi.org/10.7717/peerj.5497
Ng, P.K.L. (1988) The freshwater crabs of Peninsular Malaysia and Singapore. Department of Zoology, National University of Singapore, Shinglee Press, Singapore, viii + 156 pp., 63 figs., 4 colour pls.
Ng, P.K.L. (1996) On a new genus and new species of potamid crab (Brachyura) from Burma. Crustaceana, 69 (8), 1005–1013.
Ng, P.K.L. & Tay, F.W.M. (2001) The freshwater crabs of Sri Lanka (Decapoda: Brachyura: parathelphusidae), Zeylanica, 6 (2), 113–199.
Ortmann, A.E. (1986) Das System der decapoden-Krebse. Zoologische Jahrbücher. Abteilungfür Systematik, Geographie und Biologie der Thiere, 9, 409–453.
Pati, S.K. & Thakeray, T. (2018) The freshwater crab genera GhatianaPati& Sharma, GubernatorianaBott, and InglethelphusaBott (Crustacea: Decapoda: Brachyura: Gecarcinucidae) revisited, with descriptions of a new genus and eleven new species. Zootaxa, 4440 (1), 1–73.
https://doi.org/10.11646/zootaxa.4440.1.1
Pati, S.K., Mitra, S & Yeo, D.C.J. (2019) New species of Acanthopotamon Kemp, 1918 (Decapoda: Brachyura: Potamidae: Potaminae) from northeastern India, with a key to the species of the genus and notes on their distribution in relation to freshwater ecoregions. Journal of Crustacean Biology, 39, 450-458.
https://doi.org/10.1093/jcbiol/ruz040
Roy, T., Ghosh, S.K. & Ghatak, S.S. (2004) Crustacea : Decapoda : Palaemonidae and Potamonidae. In: The Director (Ed.), Fauna of Manipur. State Fauna Series, 10, pp. 119–123.
Takeda, M., Sugiyama, H. & Singh, S.T. (2012) Some freshwater crabs from Northeast India bordered on Myanmar. Journal of Teikyo Heisei University, 23, 199–213.
Wood-Mason, J. (1871) Contribution to Indian Carcinology.—On Indian and Malayan Telphusidae, Part-I. Journal of the Asiatic Society of Bengal, Part II (Physical Science), 40, 449–454.
Yeo, D.C.J. & Ng, P.K.L. (2004) Recognition of two subfamilies in the Potamidae Ortmann, 1896 (Brachyura, Potamidae) with a note on the genus Potamon Savigny, 1816.Crustaceana, 76 (10), 1219–1235.
https://doi.org/10.1163/156854003773123456
Yeo, D.C.J. & Ng, P.K.L. (2007) On the genus “Potamon” and allies in Indochina (Crustacea: Decapoda: Brachyura: Potamidae). Raffles Bulletin of Zoology, Supplement 16, 273–308.