SIZE- AND DIET-RELATED VARIATIONS IN ENZYMIC ACTIVITY AND TISSUE COMPOSITION IN THE SABLEFISH,ANOPLOPOMA FIMBRIA

Abstract

The influences of body size, ration size, season, and latitude on several biochemical properties of skeletal muscle and liver were examined in the sablefish, Anoplopoma fimbria, to understand how these factors interact to establish the biochemical and physiological condition of the organism. Activities in muscle of the glycolytic enzymes lactate dehydrogenase (LDH) and pyruvate kinase (PK) increased significantly with increasing body size. This size-dependent variation in enzymic activity must be corrected for when the effects of other enzyme activity influencing variables, e.g., ration size, are studied. Ration size had a strong influence on muscle enzyme activities and on the water and lipid content of muscle. Starvation led to large decreases in glycolytic enzyme activity and lipid content. The LDH content of muscle was directly proportional to the amount of food ingested (expressed as percent body weight ingested per day). Latitudinal differences among sablefish collected between Alaska (Bering Sea) and southern California and seasonal differences among individuals collected off southern California also may be due to varying ration quantity and quality. During starvation, lipid reserves in muscle appear to be mobilized as a major energy source in preference to protein.