Molecular characterization of two Australian temnocephalans (Temnocephalida, Platyhelminthes) introduced with alien crayfish (Parastacidae, Decapoda) into South Africa

Abstract

Abstract In our previous research on a natural waterbody in South Africa, introduced Australian redclaw crayfish, Cherax quadricarinatus, were found to harbour two species of temnocephalans on their body surfaces and branchial chambers. The temnocephalans were morphologically consistent with Craspedella pedum and Diceratocephala boschmai, both known from this host species and native originally to Australia. In the current study, we report molecular data from the same material. DNA sequences from portions of the gene encoding the nuclear ribosomal 28S RNA indicated a close relationship of these worms with those from Australia. It is highly likely that the worms we found were introduced into South Africa along with the crayfish, following a similar trend elsewhere in the world. There is no evidence that they have been able to establish on native South African hosts.