VARIATIoN oF GRoWTH PERFoRMANCE oF THE STRIPED VENuS CLAM Chamelea gallina (MoLLuSCA: BIVALVIA) (LINNAEuS, 1758) IN RELATIoN To ENVIRoNMENTAL VARIABLES ALoNG THE SouTHERN PART oF ITS GEoGRAPHIC RANGE