First record of sesarmid crab, Nanosesarma pontianacense (de Man, 1895) (Decapoda: Brachyura: Sesarmidae) in India

Abstract

The sesarmid crab, Nanosesarma pontianacense (De Man 1895), is newly recorded from the oyster beds in the Vellar estuary, the Southeast coast of India, during February–April 2025. This species was first described from Pontianak, Indonesia. N. pontianacense closely resembles N. gomantaka (Trivedi et al ., 2024) in overall appearance but can be distinguished by several diagnostic characters: carapace bilobed with a comparatively shallow V-shaped notch; external orbital angle extending beyond rudimentary; the eyestalks are short, stout, and slightly hairy; lateral margin almost parallel along the anterior half and somewhat concave along the posterior half; carapace 0.85–0.92 longer than wide with dense setose and the epibranchial tooth minute or poorly developed. The propodi of pereopods (P2–P5) are smooth, with slightly curved tips, bearing one long and two minute spines on the lateral terminal side. In males, the left G1 is relatively straight and slender, except for the distal chitinous part, which is gently bent at an obtuse angle and has a more rounded distal part of the shaft.