High species diversity of fish tapeworms in congeneric hosts in Africa: revision of Monobothrioides (Cestoda: Caryophyllidea), including description of two new species and molecular phylogeny

Molecular and morphological evaluation of tapeworms of the genus Monobothrioides Fuhrmann and Baer, 1925 (Caryophyllidea: Lytocestidae revealed their relatively high species diversity in congeneric catfishes (Siluriformes) of the genera Auchenoglanis Gunther (Claroteidae) and Clarias Scopoli (Clariidae). Molecular phylogenetic analyses of newly characterised lsrDNA and ssrDNA sequences distinguished five different lineages corresponding to morphologically well-defined species. In Clarias catfishes, two congeneric species of Monobothrioides occur, whereas as many as four tapeworm species are recognised in claroteid catfishes of the genera Auchenoglanis and Parauchenoglanis Boulenger, including two new to science. Monobothrioides longicollis n. sp. from Auchenoglanis occidentalis (Valenciennes) in the Democratic Republic of the Congo and the Sudan is characterised by a long body (up to 43 mm), with a long neck and vitelline follicles starting at a a long distance anterior to the first testes. Monobothrioides zuheiri n. sp. from A. occidentalis (type host) and A. biscutatus (Geoffroy Saint-Hilaire) in the Sudan is characterised by a small (< 15 mm), digitiform body with a scolex indistinctly separated from the body proper, widely oval cirrus-sac and the testes starting much anterior to the first vitelline follicles. Scanning electron micrographs of four species and a morphology-based key to the identification of Monobothrium spp. is also provided.