Description of a new Eimeria species and redescription of Eimeria mayeri (Protozoa: Eimeriidae) from wild reindeer Rangifer tarandus in Iceland.

Altogether, 195 fecal samples of reindeer calves (Rangifer tarandus) were collected from the ground in 3 distinct areas in eastern Iceland, where geographically isolated reindeer populations graze during the summer months. The samples were examined for coccidian parasites. Two species were found, and all infections were monospecific. Eimeria mayeri was found in calves in all sampling areas, with 1-4% prevalence and 450-167,700 oocysts per gram (opg). The sporulated oocyst lacks a polar granule but has an inconspicuous micropyle, and a small Stieda body is present on sporocysts, which are ovoid but not pointed as reported in the original description. The other coccidian, found in single calves in 2 of the 3 areas (prevalence 1 and 4%, 150 and 500 opg, respectively) is described here as a new species. The oocysts are ovoid, average 34.9 x 27.6 microm, and have 2 distinct walls. Wall thickness is approximately 1.9 microm, and the outer wall, approximately 3/4 of total thickness, is generally smooth and appears bicolored. The outermost portion is pale red and the innermost portion yellow to pale brown. The inner wall is grey to dark brown and separated from the outer wall by a dark brown line. Oocysts contain a prominent micropyle, approximately 5 microm, and enclose 4 spindle-shaped sporocysts, slightly pointed at the end opposite the Stieda body. Average size of sporocysts is 18.6 x 9.2 microm. Sporocysts contain granular sporocyst residuum and usually 2, sometimes 1, large refractile bodies in each sporozoite.