Effects of Water Temperature on Feeding and Growth of the Amphidromous Sculpin, Cottus pollux Middle-egg(ME) Type Reared in tiie Laboratory

摘要

Effects of water temperature on feeding and growth of the amphidromous sculpin Cottus pollux ME were studied using 9 different temperatures from10 to 26。C for 30 days. At each of the 9 temperatures, five males and females were reared in aquaria and the rearing examination was repeated 3 times (n = 270). Results indicate that water temperatures ranging from18 to 20°C were optimal for daily feeding rate, temperatures ranging from14 to 17°C were optimal for daily-growth rate, and feeding efficiency temperatures ranging from11to 16°C were optimal among males and females. The optimal water temperatures for daily growth rate and feeding efficiency were slightly lower than those for daily feeding rate. Also, the values by the polynomial equation of daily growth rate and feeding efficiency for 26t had lower or negative values. These results indicate that the optimal water temperature range is from14 to 20°C ， and that a water temperature of 10V- is too low and 26°C is too high for C. pollux ME to feed and grow.