Description of a New Inland Prawn, Macrobrachium Walvanense, from India (Decapoda, Palaemonidae)

A new inland palaemonid prawn belonging to the genus Macrobrachium, collected from the Walvan Dam at Lonavala, near Pune (Maharashtra State, India) is described in detail with notes on colouration, ecology, etc. Salient features of this medium-sized (total length up to 50 mm) new species are its slightly convex rostrum, extending up to the tip of the antennal scale; its rostral formula of 9-13/4-6, usually 10-12/4-5, with 2 postorbitals; the chela of the second cheliped always longer than the carpus in both sexes, and with the palm longer than the carpus only in females but shorter in males; the telson with a sharp median point; ovigerous females with 120 to 300 chalky-green eggs which have a maximum diameter of 1.02 mm. Body translucent with branched reddish-brown chromatophores extending from carpus to fingertips of second chelipeds and at joints of remaining pereiopods. Development: 9 larval + 1 postlarval stages when reared in freshwater, and 8 + 1 in water of low salinity (1.60 to 13.20 ppt). The new species differs from its close relative M. banjarae (Tiwari, 1958) with respect to rostrum, second cheliped, and telson features.