Morphological and Molecular Identification of Isospora sepetibensis (Chromista: Miozoa: Eimeriidae) from a New Host, Trichothraupis melanops (Passeriformes: Thraupidae: Tachyphoninae) in South America

Isospora sepetibensis Berto, Flausino, Luz, Ferreira and Lopes, 2008 is a protozoan coccidian parasite (Chromista: Miozoa: Coccidiomorphea: Coccidia) that was originally described from Brazilian tanagers Ramphocelus bresilius (Linnaeus, 1766) in the Marambaia Island in the Coast of the State of Rio de Janeiro. In the current  work, this species was identified from black-goggled tanagers Trichothraupis melanops (Vieillot, 1818) in the Itatiaia National Park, which is a protected area with a high degree of vulnerability in the interior of the State of Rio de Janeiro, distant in more than 100 km of the type-locality. Its oocysts are sub-spherical to elongate  ovoidal, 25.9 × 20.7 μm with smooth, bi-layered wall, ~ 1.3 μm and length/width ratio of 1.1–1.4 (1.26). Micropyle and oocyst residuum absent, but one or two polar granules are present. Sporocysts are ellipsoidal, 16.8 × 10.3 μm, with both Stieda and sub-Stieda bodies. Sporocyst residuum present  and sporozoites with refractile body and nucleus. Molecular analysis was conducted at the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. This new isolate exhibited similarity greater than 98% with Isospora spp. isolates from other Neotropical passerines and with an Isospora sp. pseudoparasite of voles of Eurasia. This is the first coccidian  parasite from a New World tanager to have a molecular identification of the cox1 gene.