Myosporidium merluccius n. g., n. sp. Infecting Muscle of Commercial Hake (Merluccius sp.) from Fisheries near Namibia

Abstract

A new species of Microsporidia classified to a new genus was observed in the trunk muscle of commercial hake (Merluccius capensis/paradoxus complex) from Namibian fisheries. Macroscopic examination revealed thin and dark filaments inserted among muscle fibers. Inside the filaments were many sporophorous vesicles with about 30–50 spores per vesicle. The shape of the spore was pyriform and the extruded polar filament was of moderate length (up to 4.29 mm, n512). This new species of Microsporidia is described using macrophotography, microphotography, staining, and transmission electron microscopy (TEM), as well as molecular methods. Its 16S rRNA was found to be similar to that of Microsporidium prosopium Kent et al., 1999, while both sequences were quite different from 16S rRNA sequences known for other Microsporidia. Nevertheless, this new species is separated morphologically from M. prosopium by the presence of 11–12 anisofilar coils and the formation of the xenoma at the site of infection. Type species