Macrobrachium malayanum (J. Roux 1935)

Macrobrachium malayanum (J. Roux, 1935)

Palaemon (Macrobrachium) pilimanus malayanus J. Roux, 935b:32 [type locality: “Lasah, Plus Valley, East Perak,” Malay Peninsula].

Macrobrachium geron Holthuis, 1950a:258, fig. 52 [type locality: Pulau Bangka, east of Sumatra, Indonesia].

Macrobrachium malayanum.—Chong and Khoo, 1987a:904, figs. 1–3,4a.

DIAGNOSIS.—Rostrum not or barely overreaching antennal scale, dorsal margin straight or convex, rostral formula: 3–4 + 5–8/3–6, dorsal teeth slightly more widely spaced posteriorly than anteriorly; branchiostegal suture not extending posteriorly beyond hepatic spine; telson with posterior apex not overreaching posterolateral spines; antennal scale with lateral margin nearly straight; 1st pereopod with chela more than as long as carpus; 2nd pereopods unequal in length and dissimilar in form; major 2nd pereopod with palm compressed, fingers and palm covered with dense carpet of short velvety hair, fingers dentate on opposable margins, not widely gaping, chela at least twice as long as carpus, no longer than merus; minor 2nd pereopod with fingers slightly shorter than palm; maximum postorbital carapace length about 17 mm.

RANGE.—Peninsular Malaysia, Singapore, Sumatra, Borneo; slow to rapid flowing streams in or near forested areas.