Vitamin contents in the lamprey, Entosphenus japonicus Martens.

Abstract

Vitamin contents were tested with the lamprey caught in the Mogami River, Yamagata Prefecture. In the flesh, the vitamin A level was found the highest ever known in the flesh of any species of fish or animal. Anatomical parts rich in vitamin A next to the flesh are the liver, kidney, gonads and intestine; especially, the testis and intenstine contain extraordinary quantities of the vitamin. The distribution of vitamin A in the body considerably differs from that of ordinary fishes. The major part of the vitamin is accumulated in the flesh and intestine, whereas the liver possesses only a small part of it.Samples caught in the spawning season, April and May, were found more abundant in the vitamin content than those canght in autumn. The young fish also indicated by far higher content of vitamin A than any other fish in a comparable stage.The content of thiamine and B12 in the skin greatly exceeds that of other fishes. In the ventral skin more thiamine was found than in the dorsal skin.