Presence of the alpheid shrimp genus Potamalpheops Powell, 1979 (Crustacea : Decapoda : Caridea) in South Asia, with description of a new species from Sri Lanka

A new species of the alpheid shrimp genus Potamalpheops Powell, 1979, is described on the basis of a single male specimen collected in a brackish water stream, 6 km from the sea, in southern Sri Lanka. Potamalpheops galle, new species, differs from all other species of the genus by a combination of several features, and appears to be closest to the South-East Asian species R amnieus Yeo & Ng, 1997, P. miyai Yeo & Ng, 1997 and P. palawanensis Cai & Anker, 2004. The new species is the first record of Potamalpheops in South Asia and constitutes an important link between two major radiation zones of this genus, West Africa and South-East Asia/Australia.