The conservation status of decapod crustaceans in the Western Ghats of India: an exceptional region of freshwater biodiversity

Abstract

Freshwater invertebrates receive relatively little publicity and conservation attention, in spite of their key role in aquatic food webs and ecosystem functioning.Decapod crustaceans such as caridean shrimps and gecarcinucid freshwater crabs comprise some of the most poorly known aquatic taxa, even in exceptional regions of freshwater biodiversity and endemism, such as the Western Ghats mountains of peninsular India.An analysis was carried out to understand distribution patterns and identify priority areas for decapod crustacean conservation in the Western Ghats region based on conservation status data retrieved from the IUCN Red List of Threatened Species.The Western Ghats region is home to 49 species and six sub?species of caridean shrimps (69% endemism) in four genera and two families, and 39 species of gecarcinucid crabs (92% endemism) in 14 genera. This diversity is probably an underestimate given the lack of biotic surveys and taxonomic research carried out on these groups.Three species (3%) of decapod crustaceans from the Western Ghats region are threatened with extinction, while more than half (51%; 48 species) are Data Deficient. The uncertainty regarding the true extinction risk of such a high number of Data Deficient species could hamper conservation efforts as well as policy development and implementation.Forty sites in the Western Ghats region are priorities for the conservation of decapod crustaceans, of which only seven lie within the existing network of protected areas.The specialized natural history and point endemic nature of many species of freshwater decapods, together with escalating human impacts on their aquatic ecosystems in the Western Ghats, makes conservation and management of these threatened and poorly?known species an immediate and urgent challenge.