Biochemical Characteristics of Chum Salmon Muscle during Spawning Migration

Abstract

The relation between gonadosomatic index (GSI) value and proximate composition of muscle of chum salmon at each migration stage did not markedly differ with the date and locality of capture. This might suggest that the situation of proximate composition can be characterized by the GSI value. The relation between GSI value and proximate composition was statistically evaluated by multiple regression analysis. Total protein and sarcoplasmic protein contents of the muscle markedly decreased during spawning migration, while the contents of ninhydrin positive substances of non-protein nitrogenous compounds increased. A high level of muscle autolytic activity was observed in the muscle of the fish during spawning migration. The composition of muscle protein fractions at the same migratory stage did not differ greatly from fish to fish, regardless of the date and locality of capture. Judging from the fact that proximate composition, protein composition, and autolytic activity of chum salmon muscle at the same migratory stage were almost the same regardless of the date and locality of capture, the changes described above during spawning migration were considered to be closely related to their physiological states. © 1986, The Japanese Society of Fisheries Science. All rights reserved.