D-shaped nematode eggs in the feces of Rangifer tarandus: A story in pictures

Abstract

Abstract D-shaped nematode eggs in Rangifer tarandus feces are expected to be oxyurid nematodes of the genus Skrjabinema. The species S. tarandi is considered species-specific for this host. There is no consensus regarding the cross-infection of reindeer and sheep with S. ovis and S. tarandi. The drawings proposed by researchers complicate differential diagnostics. Micrographs of S. tarandi eggs obtained via light microscopy and scanning electron microscopy, as well as photographs of S. ovis eggs, and drawings made on their basis, are proposed to confidently distinguishing between representatives of these two species, taking into account morphometric data. Thus, the egg of S. tarandi has a thickening on the convex side, in contrast to the egg of S. ovis. It is shown that due to the specific feeding habits of R. tarandus, D-shaped eggs of parasitic nematodes of small rodents can also be found in their feces. The latter should be considered spurious parasites.