Linking valve closure behavior and sodium transport mechanism in freshwater clam Corbicula fluminea in response to copper.

The purpose of this study is to develop a mechanistic model to describe a conceptually new "flux-biological response" approach based on biotic ligand model (BLM) and Michaelis-Menten (M-M) kinetics to allow the linkage between valve closure behavior and sodium (Na) transport mechanism in freshwater clam Corbicula fluminea in response to waterborne copper (Cu). We test the proposed model against published data regarding Na uptake kinetics in rainbow trout and Na uptake profile in C. fluminea, confirming that the predictive model is robust. Here, we show that the predicted M-M maximum Cu internalization flux in C. fluminea is 0.369 micromolg(-1)h(-1) with a half-saturation affinity constant of 7.87x10(-3) microM. Dynamics of Na uptake and valve closure daily rhythm driven by external Cu can also be predicted simultaneously. We suggest that this "Na transport-valve closure behavior" approach might provide the basis of a future design of biomonitoring tool.