Freshwater bivalve fauna in the western ghats rivers of karnataka, India: diversity, distribution patterns, threats and conservation needs

The diversity and distribution patterns of freshwater bivalves have been studied from January 2006 to December 2006 in the Western Ghats Rivers of Karnataka, India. The study was carried out in different sampling sites of 20 rivers. A total of 19 species of freshwater bivalves belonging to 3 families were recorded during the study period. Of these, a total of 15, 3 and 1 species of bivalves belong to families Unionidae, Corbiculidae and Etheriidae, respectively. All the species represented by five genus viz, Parreysia-9 species Lamellidens-5 species Corbicula-3 species, whereas Arcidopsis and Pseudomulleria represented with one species each. The population density of bivalves was high in river Cauvery and P. corrugata was the most common species found in 17 rivers followed by L. marginalis (15 rivers). In the present study, three species of the bivalves are not assessed (endemic-Arcidopsis footie, Parreysia khadakvaslaensis; non endemic-C. cashmiriensis), Pseudomulleria dalyi is assessed as endangered and endemic, whereas P. cylindrica is listed as Data Deficient and rest of the 14 species are listed in Least Concern category by International Union for Conservation of Nature (IUCN).