Homalopsine Snakes is a review of the aquatic rear-fanged snakes that inhabit freshwater, brackish water, and marine environments from Pakistan's Indus River eastward to Queensland, Australia. While a few live in flowing streams with clear water and rocky bottoms, most live in the muddy habitats created by Himalayan silt flowing to the seas of Southeast Asia. Many feed on fish, but a few have adapted to feeding on crustaceans and some are commensal with crustaceans living in their burrows. The Indochinese Peninsula and Sunda Shelf contain the greatest species diversity, and the history of these snakes is closely tied to the changing landscape of Southeast Asia.