Abstract
A new coccidian species, Eimeria erythrorhynchosi n. sp. (Apicomplexa: Eimeriidae) collected from the American white pelican Pelecanus erythrorhynchos Gmelin 1789, is reported from Toluca city, Mexico. Sporulated oocysts of the new species are ovoidal, 17.5-19.6 × 14.1-14.8 (18.5 × 14.5) μm, with a length/width (L/W) ratio of 1.0-1.5 (1.25); micropyle present, robust and protruding, W: 4.5-5.5, and polar body (1 or 2), L × W: 2.5 (2-3), associated with the micropyle; oocyst residuum absent. Sporocysts are ovoidal, 10.1-11.2 × 6.4-7.1 (10.7 × 6.8) μm, with a length/width (L/W) ratio of 1.0-1.6 (1.3); Stieda and sub-Stieda bodies are both present, but para-Stieda body is absent; sporocyst residuum of diffuse granules. Sporozoites are vermiform, 9.6 × 2.4 μm. The new species is the seventh species of Eimeria recorded in Pelecaniformes and the third in Pelecanidae.