Seasonal rainfall patterns of the Western Ghats necessitate a period of dormancy for its land snails, resulting in their high abundance and diversity including at least 258 species of gastropods from 57 genera and 24 families. A total of 77 species of freshwater molluscs (52 gastropods and 25 bivalves) have been recorded from the Western Ghats, but the actual number is likely higher. This include 28 endemics. Among the threatened freshwater molluscs are the mussels Pseudomulleria dalyi, which is a Gondwanan relict, and the snail Cremnoconchus, which is restricted to the spray zone of waterfalls. According to the IUCN, 4 species of freshwater molluscs are considered endangered and 3 are vulnerable. An additional 19 species are considered data deficient..