Authors

Discussion

The African continent has a rich diversity of fish and amphibians in its inland water systems that, serve as hosts for seven genera of Gyrodactylidae. In August, 2011, eight gyrodactylid parasites were collected from the gills of two specimens of bulldog, Marcusenius macrolepidotus (TL=25.3–28 cm), from Lake Kariba. Morphometric evaluation and sequencing of 18S rDNA confirmed that the specimens represented a new viviparous genus of this family. The attachment apparatus consists of a single pair of large slender hamuli with prominently flattened roots that are connected by a simple, thin dorsal bar. The ventral bar is small and possesses no evident ventral bar membrane nor lateral processes. There are sixteen marginal hooks of one morphological type, but of three different sizes, with large falculate sickles that are proportionately equal in length to that of their handles. The two largest pairs of marginal hooks are positioned closest to the opisthaptoral peduncle, and the neighbouring four pairs of medium-sized marginal hook sickles are situated along the lateral margins of the opisthaptor. The remaining two pairs, and smallest marginal hooks are positioned along the posterior margin of the opisthaptor. The male copulatory organ consists of a muscular pouch armed with approximately 30 gracile spines. Phylogenetic analyses constructed on partial sequences of the 18S rDNA using Maximum Likelihood and Bayesian Inference using a GTR+I+γ phylogenetic model placed the new genus within the lineage of solely African genera. Based on uncorrected p-distances, Diplogyrodactylus martini appears as the closest related to the new genus.