Histological observation of gonadogenesis and gametogenesis in Koi carp.
小川, 智史 ,
佐藤, 将 ,
兵藤, 則行 ,
中村, 將平井, 俊朗
帝京科学大学紀要 = Bulletin of Teikyo University of Science
75 , 2015-03-31
Koi carp（coloured carp）is a major ornamental fish in the world, originating from colored mutants arose in culturedcommon carp（Cyprinus carpio ）populations for food at Niigata area, Japan, in the late Edo period. In this fish, effectivemethods for functional masculinization of genetic-female（XX）are required to make all-female sibling because of their highercommodity value. Sex hormone, especially estrogen is a key regulator of sex differentiation in fish, and therefore administrationof sex steroid during sexually labile stage in early development is conventionally used for sex control in aquaculture. It isessential to define the appropriate dose and timing of hormonal administration for successful sex reversal, and histologicalanalysis provides crucial information. Histological data archive can be used as a valuation basis for a precise assessment ofganadal status. In Koi carp, however, there is no integrated description from early development of gonad to maturation. In thisreport, we outline the histological features of gonadogenesis and gametogenesis of Koi carp.