A FIELD EXPERIMENTAL STUDY ON THE EFFECT OF FOOD ENVIRONMENT ON THE GROWTH OF CAGED CORBICULA JAPONICA

Abstract

 The purpose of this study is to disclose relation of the food source with the growth of bivalve Corbicula japonica through a 61 day's caging experiment in the riverine field. The experiment at three stations in the Natori River indicated marked differences in growth of the bivalve among stations, that the highest growth was recorded at St. 2 where the major fishery grounds were formed. No relation between growth rate and supplied POM were detected at each station. No significant difference in stable isotope ratios of POM was observed among stations. The C/ N ratio and the carbon content of SOM were higher at St. 2. SOM would be the important factors on food condition for C. japonica feeding on sediments. These results suggested that high contribution of the terrestrial organic matter in the bottom layer to C. japonica as a carbon food source.