The vitamin A content of heteroscymnus longus Tanaka, a kind of deep sea shark.

Regarding the distribution of vitamin A in the bodies of fish, there are two types of accumulation: one accumulates most of the vitamin A in the liver, and sometimes in the pyloric caeca also, but very little in the flesh; while the other type accumulates several times more vitamin in the flesh than in the liver. To the former type belong most species of commer cial fish, e. g. sharks, tuna, skiplack, and flatfishes; while a few species including eel, conger eel, and lamprey (Cyclostomata) belong to the latter type. The vitamin A content in viscera and eggs of deep sea sharks in general, is by far less than that of surface sharks and common teleostei. Particularly the flesh of deep sea sharks contains very little fat and vitamin A. An important exception, however, is "kaeruzame", eteroscymnus longus Tanaka, a kind of deep sea shark. Although the fish belongs to the first type in regard to the anatomical distribution of vitamin A, the flesh of this species contains a nearly equal amount of vitamin A to that of the second type, and over hundreds of times as much as that of common edible fish. Except for the lamprey, the vitamin A content of "kaeruzame" is the highest of all the animals so far investigated. "Kaeruzame" has occasionally been caught in the waters off Kanagawa