Influence of daily water temperature changes on the chemiluminescent response and mortality of cultured rockfish ( Sebastes schlegeli)

Abstract

To elucidate whether daily water temperature changes influence chemiluminescent response, plasma glucose level and mortality of cultured rockfish ( Sebastes schlegeli), three experimental temperature groups were established. The fish in group I were maintained constantly at 27°C, and those in groups II and III were exposed to daily elevation of water temperature from 27°C to 28°C and 20°C to 22°C for 5 h, respectively. After 1 week of being maintained in each experimental tank, the fish in groups II and III showed significantly lower CL peak values ( P<0.05) and significantly higher plasma glucose levels ( P<0.05) than those in group I. The cumulative mortality of group III was 100% within 4 days after anaesthetization and blood collection. On the other hand, the cumulative mortalities of groups I and II were 33.3% and 16.7%, respectively.