Protogynous hermaphroditism in Crustacea: a new example from Tanaidacea

Hermaphroditism has been widely reported in the Crustacea, but protogyny, which females change to males, is apparently rare and restricted peracarid orders Isopoda Tanaidacea. In latter, protogyny demonstrated only seven species representing six genera by rearing experiments indicated for several other through morphology. Here, we show experiment histological observations, protogynous hermaphroditism tanaidacean Nesotanais sp. aff. ryukyuensis Kakui, Kajihara Mawatari, 2010. Our size distribution data wild individuals showed that can sex at various sizes (= ages). We found one individual identified externally as a female containing both ovaries testes, indicating overt undergo short transitional phase simultaneous hermaphrodites before sex-change molt. discuss relationship among wide of sex-changing females, life span tube-dwelling mode life.