Occurrence and characterisation of tongue worms, Linguatula spp., in South Africa

A total of 509 mammalian vertebrates, belonging to 76 species, were examined for infection with pentastomid parasites. These animals were from 8 of the 9 provinces in South Africa. Linguatulid pentastomes were found only in 7 animals, specifically the African Lion (n = 3) and African Buffalo (n = 4). Adult parasites were found in the lion but nymphs, of various stages, were found in the buffalo. A detailed morphological examination of adult parasites using both light and scanning electron microscopy techniques suggested the specimens were Linguatula nuttalli Sambon1922. Sequences of 18S ribosomal DNA and Cox1 regions obtained from both adult and nymph stages suggested they belong to the one species. Phylogenetic analyses of Linguatula spp. based on the 18S and Cox1 sequences available in GenBank and obtained in the present study showed a clear distinction between L. nuttalli, L. arctica and L. serrata (from Europe and Australia). Several specimens from the Palearctic region which were previously assumed to be L. serrata formed a distinct group in the phylogenetic tree suggesting they probably belong to a different, and as of yet, unknown species.