Digenetic trematodes parasitic in anurans from rainforest biotopes in Edo State, Nigeria

Abstract

Digenetic trematodes parasitising amphibians in four rainforest locations (Okomu National Park, Ikoro, Ugbine, and Odighi) in Edo State, Nigeria, were investigated. The amphibians were collected using the Acoustic Encounter Survey (AES) and the Visual Acoustic Encounter Survey (VES) techniques. Of the 848 anurans examined from the four locations, 163 were infected, with an overall prevalence of 19.22%. In all, eight trematode parasites were found. At the Okomu National Park, six digenetic trematodes, including Mesocoelium monas, Mesocoelium monodi, Mesocoelium cameroonensis, Halipegus sp., Diplodiscus fischthalicus and Ostioloides rappiae were encountered in the amphibians examined. Whereas M. cameroonensis and D. fischthalicus were recovered only from Ptychadena oxyrynchus and Pty. pumilio, respectively, the other trematodes were multi-host parasites. At Ikoro, Amietophrynus regularis and A. maculatus examined were infected with M. monodi, while M. monas was haboured by Pty. mascareniensis, Pty. bibroni, Pty. pumilio and Pty. oxyrynchus. Apart from M. monodi and M. monas harboured by A. maculatus and Ptychadena spp., respectively, a third trematode, Haplometroides eburnense was recovered from Amnirana albolabris at Ikoro. Anurans from Ugbine harboured three Mesocoelium spp and Haematoloechus exoterorchis. At Odighi, Pty. oxyrynchus, Pty. mascreniensis, Pty. bibroni and Pty. pumilio harboured Mesocoelium monas while A. regularis and A. maculatus were hosts to M. monodi. Mesocoelium cameroonensis, O. rappiae and H. eburnense are new geographical records for Nigeria, while the finding of D. fischthalicus in Pty. pumilio represents a new host record for the parasite in the country.

Keywords: rainforest, amphibians, digenetic trematodes, new geographical records

The Zoologist, 10:25-33 (2012)