Further specimens of the mud snake, Gerarda prevostiana (Homalopsidae) from Sri Lanka with insights from molecular phylogenetics

Abstract

Gerarda prevostiana is an aquatic homalopsid snake distributed in the coastal brackish water habitats from Northwestern India, through peninsular Malaysia to the Philippines. In Sri Lanka, it appears to be a rare species known only from a few specimens. During a survey on the marine snake fauna of Sri Lanka, the authors found two specimens of Gerarda prevostiana as by-catch of fisheries from a coastal region in Northwestern Sri Lanka. Comparison of morphological data of the two individuals with available literature suggested little variation with their extralimital counterparts. However, moderate mitochondrial sequence divergence (similar to 3%) between specimens from Sri Lanka and Singapore suggest a history of isolation between South Asian and Southeast Asian populations.