The contents of acid-soluble and insoluble collagens in the ordinary muscle of twenty-two species of fishes was determined. In addition, the contribution of muscle collagen to the swimm-ing movement of fish and to the texture of the sliced raw meat was examined.
The total collagen content varied with species in the ranges from 0.34 to 2.19% of wet tissue and from 1.6 to 12.4% of crude protein. The solubility of muscle collagen of fishes was generally much higner than that reported for muscle collagen of mammals. As for the swimming movement, the results indicated that the musculature of the fish with flexible body comprises a high proportion of collagen. As for the textural properties, the results indicated that the muscle collagen con-tributes to the toughness of the sliced raw meat.