Vitamin contents in the lamprey, Entosphenus japonicus Martens.

In Japan the lamprey, Entosphenus japonicus Martens, has often been recom mended since old times as a diet efficacious for curing night blindness and tuber culosis because of its rich source of nourishment. Fujimaki (1), Miura (2) and Nakamiya (3), reported the nutritive factors in the lamprey on different occasions and maintained that the vitamin A content of its flesh is several times as much as that of fresh butter or oil of the eel. Based on the works carried out by the authors in regard to the biochemical significance and variabiltiy of vitamin A in fish of different species, it can be said that the lamprey is a very unusual fish in various vitaminological aspects. The present paper deals with the results of the experiments conducted with the samples caught in the Mogami River, Yamagata Prefecture, in various seasons during 1951 to 1956.