Studies on the Opalinidae of Australian frogs : the life cycle of Zelleriella binucleata (Raff) in the frog Limnodynastes tasmaniensis Gunther

Abstract

The Opalinidae are a group of protozoa inhabiting the rectum of Anura. The systematics of the group has been the subject of much controversy. Metcalf's view (Metcalf, 1918), that the Opalinidae represent a primitive stage in the evolution of the Ciliata, has been discredited by more recent workers. A series of papers, culminating with that of Grasse (1952), has pointed out the affinities of the Opalinidae with the Flagellates. Grasse (op. cit.) created a new super-order Opalinina at the same level as the Protomonadina and Metamonadina, clearly indicating his view of their specialized evolution from existing flagellates. Corliss (1955) summarized the ciliate and the flagellate characters of the Opalinidae and agreed with Grasse as regards their specialized flagellate affinities. For these reasons the Order Protociliata of Metcalf (op. cit.) has been discarded. Show more