Santanu Mitra

A new species of freshwater crab of the genus Teretamon Yeo & Ng, 2007 (Decapoda: Brachyura: Potamidae) from Arunachal Pradesh, northeastern India

A new species of potamid crab of the genus Teretamon Yeo Ng, 2007, is described from Namdapha Tiger Reserve in Changlang district of Arunachal Pradesh, India. The new species, T. kempi n. sp., can be distinguished from its congeners by a distinct combination of carapace and gonopod characters: a relatively high carapace with a bilobed frontal margin; subquadrate sixth abdominal somite with nearly parallel lateral margins; and a relatively small G1 terminal segment with a semicircular to bluntly triangular dorsal flap. All known Teretamon species are compared with the new species, and a key for this genus is provided.

Redescription of Nerocila exocoeti Pillai, 1954 (Crustacea: Isopoda: Cymothoidae) parasitic on beloniform (Exocoetidae and Hemiramphidae) hosts with Nerocila madrasensis Ramakrishna & Ramaniah, 1978 placed into synonymy

Nerocila exocoeti Pillai, 1954 is re-described based on the neotype and additional material from exocoetid hosts. Nerocila madrasensis Ramakrishna Ramaniah, 1978 (from Madras) is placed into synonymy with N. exocoeti. Nerocila exocoeti is characterized by the presence of short coxae, postero-lateral angles of the first five pereonites not backwardly produced, pereonites 6-7 are reduced, cephalon sub-quadrate with anterior border straight; first antenna composed of eight articles and endopod of uropod half the size of exopod. Nerocila exocoeti is only known from beloniform hosts; Parexocoetus brachypterus and Exocoetus volitans (Exocoetidae); Hemiramphus sp. and Rhynchorhamphus malabaricus (Hemiramphidae) are the identified hosts for the species.

Teretamon spelaeum, a new species of freshwater crab (Crustacea: Decapoda: Potamidae) from a limestone cave in Meghalaya, India

A new species of freshwater crab of the genus Teretamon Yeo Ng, 2007 is described based on material collected from a limestone cave state of Meghalaya, in the northeastern Himalayan region of India. Teretamon spelaeum n. sp. can easily be distinguished from its congeners by a well suite of carapace and gonopod characters: a relatively wider carapace, setose chelipeds and legs, a highly reduced cornea of the eye, and a diagnostic male first gonopod that has a low rounded median dorsal flap on the terminal joint. The morphology of the new species is clearly adapted for the cave dwelling and is the first true troglobitic freshwater crab known from India.

Arcotheres borradailei (Nobili, 1906) and Pinnotheres ridgewayi Southwell, 1911: a reassessment of characters and generic assignment of species to Arcotheres Manning, 1993 (Decapoda, Brachyura, Pinnotheridae)

The identity of the pea crab, Arcotheres borradailei (Nobili, 1906) is clarified. The holotype female is re-diagnosed, figured and its recent generic assignment to Arcotheres Manning, 1993, is discussed. A second poorly known species from India and Sri Lanka that resembles A. borradailei , Pinnotheres ridgewayi Southwell, 1911, is redescribed and assigned to Arcotheres . In addition, Pinnotheres sinensis atrinae Sakai, 1939, and Pinnotheres cyclinus Shen, 1932, from East Asia are re-examined and also referred to Arcotheres .