STUDIES ON ELIMINATION OF CHLOROPHYLL-A AND INGESTION RATE IN EUTROPHIC WATER BY ANODONTA WOODIANA ELLIPTICA

The Anodonta woodiana Heude is one of the major bivalve species cultured in Dianchi in China.The intensive aquaculture of this species has led to depressed growth and increased mortality in recent years.In order to estimate the carrying capacity for anodonta in the lake,it is necessary to determine accurately the ingestion rate and the capacity of eliminating Chlorophyll-a by the anodonta.The results showed that the relationship between ingestion rate (IR) and wet weight of tissue (W) could be represented by the allometric equation IR=aWb under nature temperature (23-28℃).The IR of three-year-old anodonta (shell height and wet weight) was higher than that of the one-year-old anodonta.The three-year-old anodonta was found to be able to eliminate Chlorophyll-a better in water efficiently.By analysis of variance,we concluded that the effect of elimination was remarkable after 8 days in the lab.The enclosure study indicated that the effect of elimination was the best when the density of mussels was 4.17ind./m3.