Two strigeoid trematodes, Apatemon (Apatemon)udgracilis (Rudolphi, 1819) and Diploetomum (Dolichorchis)galaxiae n. sp.,udwhich encyst in the freshwater fish Galaxias auratus Johnston in LakeudCrescent, Tasmania.

摘要

The metacercaria and adult of Apatemon (Apatemon) gracilis (Rudolphi) and Diplostomumud(Dolichorchis) galaxiae n.sp. are described and figured. Metacercarial cysts of theseudspecies occur in different parts of the endemic fish Galaxias auratus: A. gracilis in theudbody cavity, orbit and vitreous humour, and D. galaxiae n.sp. visible as black spotsud('black-spot disease') in the musculature of the body and head. A gracilis which has notudpreviously been recorded from Australia occurs in the black duck, Anas superciliosa, whileudD. galaxiae n.sp. infects the white-faced heron, Ardea novaehollandiae. The domestic duck,udAnas platyrhynchos, is much more susceptible to experimental infection by Apatemonudgracilis than by D. galaxiae n.sp. Both flukes inhabit the upper small intestine of theirudbird hosts. The reproductive system of D. galaxiae n.sp. is amphitypic. D. galaxiae n.sp.udmost closely resembles D. heronei Srivastava, 1954 and D. ketupanensis Vidyarthi, 1937; audkey to species in the sub-genus Dolichorchis is given.