A review of the currently recognised zoogonid cercariae, including the identification and emergence ecology of Cercaria capricornia XI (Digenea: Zoogonidae) from Nassarius olivaceus (Gastropoda: Nassariidae) in Central Queensland, Australia.

Abstract

In the present study, we review the known zoogonid cercariae, summarise their life-cycles and first intermediate host distributions, and present a new cercaria, Cercaria capricornia XI (Digenea: Zoogonidae), which was found in one of three nassariid gastropods, Nassarius olivaceus (Bruguière), surveyed in the intertidal zone in the Capricornia region of Central Queensland, Australia. Morphological data and molecular analysis of the ITS2 rDNA region support placement of this cercaria in the family Zoogonidae but do not allow any further resolution of its identity. There are now fifteen cercariae described as belonging to the Zoogonidae; thirteen of these, including the present species, infect neogastropods as first intermediate hosts and two use vetigastropods. This study reinforces the pattern that the Nassariidae is by far the most commonly reported family for the Zoogonidae. Given its richness we predict that the Nassariidae will prove to harbour many more zoogonid species.