ヤマメの肝腫瘍について

Abstract

Hepatic tumors in a landlocked variety of masu salmon, yamamé, Oncorhynchus masou ishikawae, were described histopathologically. The hepatic cells of this species showed hyperfunctional features during vitellogenesis, but became atrophic after attainment of ovarian maturation. Hepatic tumors were first recognizable in these depleted livers as small neoplastic cell clusters. As the growths increased in size, many of the nodules became degenerative. It is noteworthy that tumors were found at highest incidence in the fast-growing female fish. The possibility that some components of the diet are capable of promoting tumor formation in the nutritionally disordered liver is discussed.