Two new Eimeria species (Protozoa: Eimeriidae) from wild rock ptarmigans, Lagopus muta islandorum, in Iceland.

One hundred rock ptarmigans, Lagopus muta islandorum (Faber, 1822), were collected in early October 2006 in northeastern Iceland and examined for coccidian parasites. Two Eimeria species were identified, and each is described as a new species. Sporulated oocysts of one species are ellipsoidal, 24.9 x 16.6 (19.5-30 x 14.5-19) microm. Oocysts have a small micropyle and a two-layered, smooth wall approximately 1.0 microm thick. An oocyst residuum is absent, but one to three polar granules are present. Sporocysts have a rounded end opposite a nipple-like Stieda body and are 14.3 x 6.3 (12-16.5 x 5.5-7) microm. Sporocysts contain one refractile body and a diffuse granular residuum; the entire contents of each sporocyst is enclosed by a thin membrane. Sporulated oocysts of the second eimerian are subspherical, 24.7 x 22.2 (20-28 x 18-24.5) microm. The oocysts are without a micropyle but with a two-layered wall, which is approximately 1.5 microm thick, with the outer layer having a rough surface texture. Oocyst residuum is absent, but one to two polar granules are present. Sporocysts have a rounded end opposite the nipple-like Stieda body atop a prominent sub-Stieda body and are 14.4 x 8.0 (12-15.5 x 6.5-9) microm. Sporocysts contain a diffuse granular residuum, and each sporozoite has two different-sized refractile bodies.