BIOCHEMICAL STUDIES ON SOCKEYE SALMON DURING SPAWNING MIGRATION: IV. THE NON-PROTEIN NITROGENOUS CONSTITUENTS OF THE MUSCLE

Abstract

The non-protein nitrogenous constituents of muscle of migrating sockeye salmon were investigated. These constituents were found to be the same in both male and female fish and were present in approximately the same amounts in both sexes. The histidine content of the muscle in all fish decreased to one fifth of the original value during the early stages of the migratory journey and remained at the low level thereafter. Some of the other constituents changed to a smaller extent, usually increasing in the later stages of the migration. This was especially noticeable in female fish. However, the increase in the concentration of these constituents in the muscle was due to a decrease in the amount of muscle in the fish rather than to an increase in the amounts of the compounds themselves.