Cercariae shed by Bulinus tropicus (Krauss, 1848) in the Free State, South Africa

Abstract

The present study forms part of a survey of the snail-borne trematode parasites in the Free State Province, South Africa. The planorbid mollusc Bulinus tropicus (Krauss, 1848) is the most abundant and widespread freshwater snail in this area.  Parasitological studies showed this snail to shed nine types of cercariae. Light and scanning electron microscopy was used to describe the morphology of five types of cercariae, an amphistome cercaria, three xiphidio cercariae and a cystophorous cercaria. The presumptive life cycles of these parasitic forms are discussed.

Key words: Trematoda, larvae, morphology, amphistome, xiphidio, cystophorous