Abstract:

Freshwater bivalve is a main group of freshwater community and plays important roles in freshwater ecosystems.An investigation on distribution and abundance of freshwater bivalve along the middle and lower reaches of the Ganjiang River was carried out by using quantitative and qualitative methods from November 2010 to February 2011.A total of 34 species and subspecies belonging to 14 genera,3 families were recorded.Only 8 species were found in the middle reaches of the Ganjiang River,and the species U.douglasiae,L.caveata and C.fluminea were the dominant species.All the 34 species inhabited in the lower reaches of the Ganjiang River,with the dominant species U.douglasiae,C.fluminea,A.chinensis,and L.caveata.The mean density and biomass of freshwater bivalves in the middle reach and lower reach of Ganjing River were 64±91 ind./m2,210±254 g/m2 and 267±441 ind./m2,2123±3148 g/m2,respectively.The results showed that species number,density and biomass of freshwater bivalve had an obvious decline along the longitude of middle and lower reaches of the Ganjiang River