An ultrastructural study of Brugerolleia algonquinensis gen. nov., sp. nov. (Diplomonadina; Diplomonadida), a flagellate parasite in the blood of frogs from Ontario, Canada.

A diplomonad flagellate found in the blood of frogs in Algonquin Park, Ontario is described by light and electron microscopy. Based on comparisons to earlier ultrastructural descriptions of various diplomonads, this flagellate warrants separate generic status and is consequently named Brugerolleia algonquinensis gen. nov., sp. nov. This organism measures 8.4 × 3.2 μm with the following features: paired reniform nuclei with kinetids arranged in binary axial symmetry; 3 pairs of flagella emerging from the anteriad and a pair of posteriorly directed recurrent flagella which emerge through fibrillar funnel-like structures; dimpled terminus; direct fibres posterior to the nuclei that recurve near the posterior end of the organism; concentric layers of endoplasmic reticulum; absence of mitochondria, Golgi bodies and caudal spike. The systematic position of this new genus is discussed with respect to the other diplomonads. Brugerolleia gen. nov. appears to have arisen between Octomitus spp. and Giardia spp. in the evolutionary scheme proposed by Brugerolle.