A New and Primitive Retrobursal Planarian from Australian Fresh Waters (Platyhelminthes, Turbellaria, Tricladida)

Abstract

A primitive freshwater planarian, Eviella hynesae gen. et sp. nov. is described from Australia. It is characterized by its lack of eyes and pigment, possession of caudally branched oviducts, and fully fused testes. Although a primary bursa is absent, its function being taken over by the modified female genital canal, the female copulatory system is posterior to the male system. Despite this maricolan feature, and other similarities with primitive southern hemisphere freshwater planarians that have been classified in the Maricola, the present species is placed in the family Dugesiidae of the Paludicola. Evidence from its sensory organs suggests that it belongs on the main evolutionary line from which the majority of Australasian freshwater planarians have been derived.