Abstract
Sequential hermaphroditism (sex change) has been reported in many decapod crustaceans, but it has not been fully reviewed to date. In this review, I have integrated and sorted descriptions regarding hermaphroditic decapod crustaceans. Eighty-five species have been recognized as hermaphrodites and 57 of those species are protandrous (male first) hermaphrodites including protandrous sex changer and protandrous-simultaneous hermaphrodite. The sexual maturation pattern of the remaining 28 species is still unclear, although simultaneous hermaphroditism has generally been speculated from sexual characteristics in their morphology or reproductive organs. Moreover, I have summarized the emerging knowledge of the adaptive significance of their sex change. After briefly reviewing theoretical works, I draw attention to recent empirical works exploring the proximal factors causing life history variation. I discuss life history variation within a population and among populations is caused by growth rate variation, mating system and diet.
