Coccidia of New World psittaciform birds (Aves: Psittaciformes): Eimeria ararae n. sp. (Apicomplexa: Eimeriidae) from the blue-and-yellow macaw Ara ararauna (Linnaeus).

In the New World, the avian order Psittaciformes comprises 142 species, yet to date only 3 (2%) of the species have been examined for coccidia, and from these only four species of Eimeria Schneider, 1875 have been described. In this study, a new coccidian species (Protozoa: Apicomplexa: Eimeriidae) obtained from the blue-and-yellow macaw Ara ararauna (Linnaeus) is reported from Brazil. Oöcysts of Eimeria ararae n. sp. are ovoidal, measure 28.7 × 20.2 µm and have a smooth, bi-layered wall c.1.1 µm thick. Both micropyle and oöcyst residuum are absent, but polar granules are present. Sporocysts are ovoidal and measure 17.0 × 8.3 µm, with knob-like, prominent Stieda body and sporocyst residuum is composed of granules; sub-Stieda body is absent. Sporozoites are vermiform with one refractile body and a nucleus. This is the fifth description of an eimerid coccidian infecting a New World psittaciform bird.