Abormon, a new genus of freshwater crab (Crustacea: Brachyura: Potamidae) from northeastern India, with descriptions of two new species

Abstract

A new genus and two new species of potamiscine freshwater crabs (Potamidae) are described from the Abor Hills in the Upper Siang District of Arunachal Pradesh State, northeastern India. Abormon gen. nov. is morphologically most similar to Pararanguna Dai and Chen, 1985, from Yunnan Province in China but can be differentiated by the setose dorsal surface and the medially concave posterolateral margins of the carapace, the concave lateral margins of the male telson, the relatively low dorsal flap on the terminal segment of the male first gonopod, and the anteriorly open and transversely ovate vulvae. Abormon capillosum sp. nov. can be distinguished from A. praecalvum sp. nov. by characters of the carapace, pereiopods, male pleonal somite 6, male gonopods, and vulvae.