Development of ‘Scope for Growth’ Assay Based on Carbon Mass Balance for Brackish Water Bivalve Corbicula japonica

Abstract

The aim of the present study is to develop a simple modified method for scope for growth (SFG) assay of Corbicula japonica using the carbon mass balance estimated from three experiments. In the clearance experiment, it was effective for putting clams into a plankton net in order to estimate the net carbon-based clearance rate by considering pseudofeces production. In the excretion experiment, it was desirable to assess cumulative POC with attention given to carbon elusion from feces to estimate the carbon-based excretion rate. In the respiration experiment, it was desirable to put a paraffin liquid on the sample surface in order to prevent CO₂ contamination prior to DIC analysis for the estimation of the carbon-based respiration rate. The modified method was applied to clams exposed to different salinities. Clams exposed to 5 psu salinity showed relatively high SFG, whereas those exposed to 20 psu salinity exhibited low SFG. The results correspond to previous findings that high salinity inhibits the growth of clams.