Additional Taxonomic Information for(Copepoda: Lernaeidae) Based on Scanning Electron Microscopy and Genetic Characterization, Alongside Some Aspects of Its Ecology.

Abstract

Additional taxonomic and ecological data for the lernaeid copepodNordmann, 1832 infecting the African tigerfish,Castelnau, 1861, are presented with scanning electron micrographs, molecular characterization, and selected ecological parameters. Eighty fish were collected from Lake Kariba between October 2014 and July 2015. Scanning electron microscopy provided additional data for the morphology, including structures on the antennulae, antennae, and legs. The 18S and 28S rDNA fragments of this species were distinct from those of othertaxa but placed this species within this genus. Phylogenetically,appears closest toCapart, 1944, the only other African species for which molecular data is available. The anterior part of the second gill filament was the preferred attachment site. There was a positive correlation (Pearson correlation coefficient= 0.64;= 0.77) between the length of the parasite and the length of the fish. A positive correlation (Pearson correlation coefficient= 0.61;= 0.03) between the length of the parasite and the length of the gill filament was also observed. Although the specimens studied here are morphologically highly similar to previous reports of, some morphological variation was observed, and a revision (morphometric and genetic) of the taxon is suggested. This study provides the first detailed genetic characterization and phylogenetic information for the species.