The diversity and abundance of parasites associated with Xenopus laevis (Daudin, 1803) in selected habitats

English: The African clawed frog, Xenopus laevis, has been extensively utilised over the years for a variety of research projects. The frog proved particularly useful as parasite study material because of its diverse parasite assemblage. The parasites of Xenopus represent seven major invertebrate groups, and no less than 29 parasite species are found associated with X laevis utilising all organs except the lungs. The rich diversity of Xenopus parasites is related to the fact that the frog is primarily water living, which facilitates parasite transfer. Despite the extensive research that has been done on the parasites of Xenopus, there is little information available on parasite ecology from field based studies. It is known, however, that parasite infection levels are determined by interaction of ecological factors and parasite and host characteristics. Due to the lack of information in this respect, a field based study was undertaken to determine what impact variations in climate, ecology, host size or age, and host sex have on the diversity and infection levels of parasites of X laevis. Two ecologically different localities were chosen for the purpose of the study. Using baited traps, X laevis were collected during different months over a two year period, and the infection levels of the different parasites determined. The infection levels of parasites in hosts of different size and sex were also determined. All the parasites found in the study occurred at both localities, but infection levels sometimes differed significantly. Although the infection levels varied through the time of the study, the seasonal patterns were not always clearly defined. Definite positive or negative correlation between size and infection levels was found for most of the parasites. The relationship between host sex and infection levels was, however, inconclusive. AJthough the parasites of Xenopus have been extensively studied, a new parasite was found in the bile ducts of the frog. The cyclophyllidean plerocercoid, Valipara campylancristrota (Wedl, 1955) (Cestoda: Dilepididae), was originally recorded from the gall bladder of the tench, Tinea tinea. The morphology and life cycle of the parasite was investigated. A juvenile leech found on the external surface of X. laevis. was preliminarily identified as Marsupiobdella africana, a leech known to infect Xenopus.