Published online by Cambridge University Press: 11 May 2009
Adults of the isopod genus Holophryxus (Dajidae) occur as ectoparasites on natant decapod crustaceans, but little is known of the ecology and life-history of most species. Species of Holophryxus are thought to have a typical dajid life cycle involving an intermediate host (copepod), a definitive host (prawn) and three larval stages (epicaridium, microniscus, cryptoniscus), and the one species for which details are available fits this pattern (Coyle & Mueller, 1981). The final host is infected by the cryptoniscus, a stage superficially resembling a cirolanid isopod, and the first cryptoniscus to settle loses its isopod-like appearance and develops through a juvenile stage into a rather inflated, highly modified female (Coyle & Mueller, 1981). Any subsequent settler becomes a male, retains the small cryptoniscus body form and lives within the marsupium of the female.