Seasonal Variation in the Collagen Content of Pacific Herring Tissues

Abstract

The total amount of collagen and its relative solubility was determined in 3-year-old herring of the same population caught at two periods, June and January, representing two extremes of the sexual cycle. Sexually mature herring, caught in January, contained 40% more collagen than sexually immature fish caught in June. When fractionated into neutral salt-soluble, acid-soluble and insoluble collagen, the proportions of the three fractions remained much the same at both seasons of the year. When various tissue fractions of the fish were examined at the two seasons it was found that not only did the concentration of collagen change in the tissues with maturation but the contribution which some of the tissues made to the total body weight also changed. The skin + scales fraction contributed most to the increase in collagen in February herring. This was due partly to a higher concentration of collagen in these tissues at this season and partly to the higher proportion of skin + scales at this time of year. The significance of these findings in relation to the biochemistry of sexual maturation is considered.