Prototransversotrema steeri gen.nov., sp.nov. (Digenea: Transversotrematidae) from a South Australian fish

Abstract

Prototransversotrema steeri gen.nov., sp.nov. is found under the scales of the mullet, Aldrichetta forsteri, a euryhaline fish.It is distinguished from Transversotrema Witenberg, the only other genus of the family Transversotrematidae by the possession of an oral sucker as well as a pharynx. This necessitates alteration of the family diagnosis.Knowledge of the life-histories of Transversotrema spp. is summarized. The so-called ‘metacercariae’ found under the scales of freshwater and euryhaline fish are regarded as adults. When they have no eggs or only one egg they have probably developed in a fish which is not the normal host.P. steeri escapes from under the scales of the fish shortly after the latter is caught. It is suggested that this habit may account for the small number of species known in the family.