抄録
Three larval stages of Ismaila occulta Ho are described, including copepodid II, copepodid III, and both sexes of copepodid IV. These larvae together with their adults were found inside the cerata of a giant red nudibranch collected from Alamitos Bay, Long Beach, California. It is speculated that the free-swimming nauplius of I. occulta developed into copepodid I before infecting nudibranch and there are five copepodid stages in the life cycle. The absence of maxilliped and leg 4 in the adult I. occulta is due to the developmental arrest of these appendages in the larval stages. An analysis of the available ontogenetic information of Poecilostomatoida indicates that Splanchnotrophidae is related to Philichthyidae and Myicolidae, particularly to the former family.
