A redescription of the adult male and praniza of Gnathia africana Barnard, 1914 is provided from material collected at three localities along the South African coast and from syntypes and other material deposited by the original author. This redescription is based on light and scanning electron microscopy.
A redescription of the adult male of Caecognathia cryptopais (Barnard, 1925) is provided from syntypes and other material deposited in the South African Museum. The generic status of Caecognathia cryptopais is also revised. This redescriplion is based on light and scanning electron microscopy.
Trichodina centrostrigeata Basson, Van As et Paperna, 1983 from Oreochromis mossambicus (Peters) and O. niloticus (Linnaeus) from different host populations from Argentina, Mexico and South Africa was reviewed. Although T. centrostrigeata has a distinct denticle structure that makes morphological taxonomic inferences uncomplicated, variation of the denticles within and among individuals and populations were still observed. While traditional taxonomy of mobilines is heavily reliant on morphometrics, and recently even more so on molecular analysis, this paper proposes the use of geometric morphometry, specifically elliptical Fourier analysis, to address morphological conflicts that arise when comparing different populations. By applying this technique, combined with traditional taxonomy, it was found that T. centrostrigeata in this study can be grouped into two separate morphotypes, the first (type a) from aquaculture farms in Argentina and Mexico and the second (type b) from a natural habitat in Glen Alpine Dam, South Africa. This study supports the validity of geometric morphometry as an additional technique to distinguish not only between species but also evolutionary plasticity of the same species from different localities and habitats.
Haematophagous larvae of a gnathiid isopod were collected from the gills, nares and buccal cavity of a single leopard catshark Poroderma pantherinum (Smith, 1838) at Jeffreys Bay and five puffadder shysharks Haploblepharus edwardsii (Voight, 1832) and one blackspotted electric ray Torpedo fuscomaculata Peters, 1855, at the De Hoop Nature Reserve on the South African south coast. Larvae were kept in fresh seawater until their moult into adult stages. The morphology of the adult males did not conform to that of any known species and they are therefore described as Gnathia pantherina sp. n. The descriptions of the adult male, female and praniza larva are based on light and scanning electron microscopy observations. Characteristic features of this species include the large size of all the final life-cycle stages, the deeply divided mediofrontal process of the male, the morphology of the pylopods and maxillipedes of the female, and the number of teeth on the mandibles (eight) and maxillules (seven) of the praniza larvae.
A redescription of the female of the temporary fish parasite, Gnathia africana Barnard, 1914 is provided from specimens reared from final-stage G. africana praniza larvae collected from their intertidal fish hosts along the south coast of southern Africa. It differs from other known gnathiid females in the shape of the frontal border and the number and basic form of pylopod articles. This redescription aims to establish a format for future descriptions and redescriptions of gnathiid females.