Geographical Distribution of Zellerielles

Abstract

REPORTING the occurrence of zellerielles in frogs at Capetown, Sandon¹ reviewed literature on the distribution of the genus geographically and by host families. He contends that the presence of Cape zellerielles is most easily explained on the basis of former land connexions with the other southern continents. Sandon noted that the American and Australian species are confined for the most part to the toothed bufonids and, following Metcalf², discounted the Asiatic record of Zelleriella macronucleata (Bezzenberger) 1904 from Bufo melanostictus. Nie's³ finding of a zellerielle in Microhyla ornata at Nanking, however, establishes it as an Asiatic genus as well. While Wenrich⁴ has shown that host specificity of the Opalinidæ is much less rigid than Metcalf supposed, the fact that in Asia (Microhylidæ) and in South Africa (Ranidæ) the host families are not toothed bufonids may be significant. Further, daCunha and Penido⁵ have found a Zelleriella in a catfish in the Paraguay River, while Carini⁶ and Wenrich report others from snakes.