Abstract
BACKGROUND: Freshwater crabs of the Western Ghats have been severely underestimated in their diversity.Since freshwater crabs have a small spatial scale endemism, many remote and poorly studied localities in the Western Ghats need to be surveyed. In this study, a new genus and new species is described. RESULTS: Arcithelphusa cochleariformis gen. et sp. nov. is described from Ondayangadi, Wayanad district, Kerala, India. The new genus and new species is exceptional among Indian freshwater crabs due to its squarish, highly arched carapace, appearing box-like in frontal view, and long, stout, spoon-shaped male first gonopod. CONCLUSIONS: With the current discovery, 14 genera and 36 species of gecarcinucid freshwater crabs are recognized in the Western Ghats of India. More new taxa can be expected from this exceptionally biodiversity-rich area if the necessary surveys are done.