Metabolic Response to Acclimation Temperature in Carp

Abstract

In order to investigate the effect of acclimation temperature on body composition, hepatopancreatic enzyme activities, and fatty acid synthesis in carp Cyprinus carpio, the fish were reared at the same feeding rate on a commercial diet at high (27°C) or low (17°C) water temperature. The contents of body fat and hepatopancreatic glycogen together with apparent fat retention were higher in the cold-acclimated fish than in the warm-acclimated fish. Most of hepatopancreatic enzyme activities were high in the cold-acclimated fish, suggesting thermal compensation for low acclimation temperature in the poikilothermic animal. The activities of lipogenic enzymes such as glucose-6-phosphate dehydrogenase and NADP-malate dehydrogenase, the level of serum triglyceride, and the rate of fatty acid synthesis from 14C-glucose and -alanine were also higher in the cold-acclimated fish than in the warm-acclimated fish. The results indicate that the fatty acid synthesis from glucose and amino acid in the hepatopan-creas of carp is activated during cold acclimation, resulting in the accumulation of body fat. © 1995, The Japanese Society of Fisheries Science. All rights reserved.