PARAMPHISTOME DIGENEANS FROM XENOPUS SPECIES (PIPIDAE) IN AFRICA - TAXONOMY, HOST-SPECIFICITY AND BIOGEOGRAPHY

The taxonomy, host range and geographical distribution of paramphistom e digeneans from Xenopus spp. in sub-Saharan Africa are reviewed. Two representatives of Progonimodiscus Vercammen-Grandjean, 1960 are recog nised, both of which are narrowly or primarily specific to Xenopns. An analysis of morphometric and meristic characters indicated geographic al variation in Progonimodiscus doyeri (Ortlepp, 1926), with two allop atric forms showing significant, but continuous, variation in testis s ize and vitelline follicle number. P. colubrifer n. sp. is distinguish ed from P. doyeri by the form of muscular elevations on the acetabulum accessory peduncle. It infects Xenopus (Silurana) tropicalis-like toa ds from lowland tropical rain forest zones in Nigeria, Togo and the Iv ory Coast, while P. doyeri occurs in hosts of the subgenus Xenopus fro m a wide variety of biotypes. Previous literature records indicate the presence of the southern P. doyeri morphological variant in X. laevis laevis in South Africa and Zimbabwe and the northern variant in X. l. victorianus, X. fraseri aff. and X. muelleri in the Democratic Republ ic of Congo, X. wittei in Uganda and the Democratic Republic of Congo, and the ranid Conraua crassipes in Cameroon (the only record of Progo nimoniscus from a non-pipid host). New host and/or geographical record s for this species are of the northern form in X. l. victorianus, X. l . bunyoniensis and X. vestitus in Uganda, X. l. sudanensis in Cameroon , X. borealis in Kenya, X. pygmaeus in the Democratic Republic of Cong o, X. fraseri aff. in Cameroon, X. wittei aff. in the Democratic Repub lic of Congo and X. muelleri in Cameroon and Nigeria. While the geogra phical limits of the two P. doyeri variants are not known with precisi on, existing data are consistent with a ''turnover'' in the region of 15 degrees S, where a notable discontinuity occurs in the distribution s of other Xenopus parasites. Species of Diplodiscus Diesing, 1836 in Xenopus hosts are rare. Diplodiscus peregrinator n. sp. was recovered from X. tropicalis at a single locality in the Ivory Coast and disting uished by a combination of body size, egg size, genital pore position and acetabulum morphology. D. fischthalicus Meskal, 1970 was not found during the present study.