Myxidium-Immersum (Protozoa, Myxosporea) of the Cane Toad, Bufo-Marinus, in Australian Anura, With a Synopsis of the Genus in Amphibians

Abstract

Myxidium immersum (Lutz, 1889), a gall-bladder protozoan parasite from South American Anura, is described for the first time in some Australian Anura. The cane toad, Bufo marinus, one of its natural hosts in South America, was introduced into Australia in 1935, and this led to the infection of native Australian frogs including: Hylidae, 12 species of Litoria; Myobatrachidae, four species of Limnodynastes, one each of Mixophyes, Ranidella and Uperoleia. Scanning electron microscope observations on the spore are reported. A synopsis of the Myxidium species in amphibians is presented. In explaining the present distribution of M. immersum in Australia, it is suggested that the life cycle of Myxidium species in amphibians involves an intermediate host which may become infected by swallowing trophozoites and spores; the tadpole may become infected by feeding on the intermediate host.