Description of a new species of Pilarta Bahir & Yeo, 2007 (Crustacea: Brachyura: Gecarcinucidae) from the Southern Western Ghats, Kerala, India.

A new species of gecarcinucid freshwater crab Pilarta vaman sp. nov. is described from Gavi, Southern Western Ghats, Kerala, Southern India. The new species differs from P. anuka Bahir & Yeo, 2007, by its more quadrate carapace with an extremely shallow cervical groove that is almost undiscernible, as well as the proportionately longer terminal article and more convex outer margins of the subterminal article of the male first gonopod; from P. aroma Pati, Rajesh, Raj, Sheeja, Kumar & Sureshan, 2017, by its low subtruncate inner angle of the carpus of the cheliped, and the narrower proximal part of the subterminal article and shape of the terminal article of the male first gonopod; and from P. punctatissima Pati, Rajesh, Raj, Sheeja, Kumar & Sureshan, 2017, by the carapace and the surfaces of the chela being weakly punctate, the male pleonal somite 6 has the lateral margins gently concave and the overall male first gonopod being more elongate.