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.

The things they carried: The pathogenic effects of old and new parasites following the intercontinental invasion of the Australian cane toad (Rhinella marina)

“…Most of these protozoans have not been shown to exert pathogenic effects on their hosts ( Delvinquier and Freeland, 1988b ), but infections by Zelleriella and Saccamoeba are associated with greater susceptibility to other parasites ( Freeland et al., 1986 ). Host-shifting of Zelleriella from cane toads to native anurans has been unsuccessful, as the parasite is only able to survive for a short time within these unfamiliar hosts ( Delvinquier and Freeland, 1988a ).…”

Opalinidae in African Anura. IV. Genus Protoopalina

“…In a series of experimental infections, Delvinquier & Freeland (1988) showed that tadpoles of X. laevis could acquire, through ingestion of cysts, and retain ZellerieUa antilliensis, a species normally occurring in the Neotropical toad Bufo marinus. The same observations, using the same opalinid, were made for various tadpole stages of different species of Australian Hylidae (Pelodryadidae) and Myobatrachidae (see Delvinquier & Freeland, 1988); but it was never found to occur in any Australian frogs, whereas it was commonly observed in the introduced Bufo marinus (see Delvinquier, 1987;Delvinquier & Freeland, 1988). McArthur (1955) unsuccessfully transferred Opalina obtrigonoidea Metcalf, 1923 from Rana pipiens (Ranidae) to X. laevis larvae.…”

Opalinidae (Sarcomastigophora) in North American Amphibia. GenusProtoopalina Metcalf, 1918

“…Karyokinesis and cytokinesis are not always synchronous (Wessenberg, 1978). In Zelleriella antilliensis (Metcalf, 1914), Delvinquier & Freeland (1988) showed that cytokinesis would not occur if the ratio of total nuclear surface to total cell surface was 5-7%. This ratio was retained in both multinucleate and mononucleate forms of Z. antilliensis.…”