Observations on Zelleriella-Antilliensis (Protozoa, Opalinata) From the Cane Toad Bufo-Marinus in Australia

Abstract

Zelleriella antilliensis (Metcalf, 1914) was found in Australia in the cloaca of the introduced American cane toad, Bufo marinus (Linnaeus, 1758). Drawings and measurements (length, width) were made with the help of a camera lucida. Other measurements were performed with the help of a digitiser. The presence of some native anuran Protoopalina spp. was noticed. 657 native Anura in 61 species and 4 families checked for Z. antilliensis were negative. Experimental infections of various anuran tadpoles of the genus Limnodynastes, Litoria and Xenopus, show that the opalinid can only survive for a limited time in these unnatural hosts. Cyst viability seems not to exceed three weeks in water. Gamonts and gametes were not observed during experimental infections. It is suggested that a protrophont (mononucleate) excysts and within 24 hours after infection of the host becomes a young trophont (binucleate). Mononucleate forms observed in the adults are recognised as Z. antilliensis and not as a species of Hegneriella.