Redescription and molecular characterisation of the fish ectoparasite Anilocra capensis Leach, 1818 (Isopoda: Cymothoidae), with description of six new species of Anilocra Leach, 1818 from Africa.

Background: Anilocra capensis Leach, 1818 is the only named species of Anilocra Leach, 1818 from South Africa. Anilocra is a large genus (> 40 species) with high levels of diversity reported from the Caribbean and Indo-West Pacific. Considering it is highly unlikely that all records of Anilocra from South Africa can be of a single species, the aim of this study was to better understand the diversity of Anilocra from this region and continent.

Methods: To redescribe A. capensis, the syntypes of A. capensis and specimens recorded as A. capensis from Africa were borrowed from the Natural History Museum, London, UK, and The iZiko South African Museum, Cape Town. Newly collected fresh samples of A. capensis were collected from off Cape Town, South Africa. Morphological redescriptions of the syntypes, and other museum and fresh material were conducted. Fresh samples were used to characterise molecularly A. capensis using the mitochondrial cytochrome c oxidase subunit 1 gene (cox1).

Results: Morphological analyses demonstrated that apart from A. capensis there are six Anilocra species new to science from Africa: Anilocra ianhudsoni n. sp., Anilocra bunkleywilliamsae n. sp., Anilocra paulsikkeli n. sp., Anilocra jovanasi n. sp., Anilocra angeladaviesae n. sp. and Anilocra hadfieldae n. sp. Of the species under study, specimens of A. capensis appear to demonstrate the most individual variation, which occurs in pleonite width, pleotelson form and uropod length. We determined that African species of Anilocra can be primarily differentiated by the proportional shape and size of the full body in dorsal view and pereonites 1, 6 and 7. Other defining morphological traits include proportional shape and size of the pereopods, and the antenna and antennula peduncles. Lastly, the molecular characterisation of A. capensis is provided and the interspecific divergence with Mediterranean species is smaller than that with Caribbean species.

Conclusions: The results of this study provide a detailed redescription of A. capensis and the first molecular barcode for this organism. Six new species of Anilocra from Africa are described, establishing that the diversity of Anilocra in this region is greater than previously known. With this new understanding of species differences, we can accurately conduct detailed molecular and ecological analyses of Anilocra from Africa with certainty of the organism under study.