Isospora lutrae n. sp. (Apicomplexa: Eimeriidae), a new coccidium from the European otter Lutra lutra (L.) (Carnivora: Mustelidae) from Spain.

Parasitological examination of European otter originating from Extremadura, Spain revealed the presence of a new isosporan species. Oöcysts of Isospora lutrae n. sp. are spherical to subspherical, 31.2 (27.5-32) x 29.6 (28-31) microm and have a smooth wall c. 1 microm thick. Sporocysts are ellipsoidal, 18.2 (17-19) x 14.4 (14-16) microm and lack Stieda and substieda bodies. A spherical sporocyst residuum is present, consisting of granules scattered among the sporozoites. Sporozoites are spindle-shaped, 12.4 x 2.5 microm and have anterior and posterior refractile bodies. Based on its unique morphologic structure and host, I. lutrae is considered to be new.