摘要：A fingernail clam, Sphaerium lacustre, was studied in subtropical Lake Donghu from June 1999 to May 2000. The S. lacustre population was characterized by a single annual reproduction period starting in March and ending in October; the population comprised three size groups, of which the 1999 cohort was dominant. The annual average density and biomass were 100.2 ind./m 2 and 12.11 g/m 2 , respectively. The annual production was 43.02 wet weight g/m 2 , and the corresponding annual production/biomass ratio was 3.55.
