Isospora oliveirai n. sp. (Chromista: Miozoa: Eimeriidae) from the Greenish Schiffornis Schiffornis virescens (Lafresnaye, 1838) (Passeriformes: Tyranni: Tityridae) in South America.

Background: Coccidia are obligatory intracellular parasites with at least one intestinal phase in their life cycles, being Isospora Schneider, 1881 the main coccidian genus related to the order Passeriformes. However, there is no record of isosporans from the passerine family Tityridae, which is the family of the greenish schiffornis Schiffornis virescens (Lafresnaye, 1838).
Purpose: This study aimed to examine the faeces from a greenish schiffornis S. virescens captured in the Itatiaia National Park, State of Rio de Janeiro, Southeastern Brazil, to determine what coccidian parasites were present.
Methods: Only one specimen of Schiffornis virescens was captured with mist nets. Coccidian oocysts were recovered from the fecal samples by flotation in Sheather's saturated solution. Morphological observations, line drawings, photomicrographs and measurements were made in optical microscopy and digitally edited. The molecular analysis included the study of the sequence of the mitochondrial cytochrome c oxidase subunit 1 (COI) gene, with phylogenetic reconstructions based on the Neighbor-Joining and Maximum Likelihood analysis.
Results: An Isospora sp. considered as new to science is described and identified from Schiffornis virescens (Lafresnaye, 1838). Isospora oliveirai n. sp. has oocysts that are subspheroidal, 26.0 × 24.8 μm, with rough, bilayered wall, c.2.5 μm thick. Micropyle and oocyst residuum absent, but one to six polar granules are present. Sporocysts lemon-shaped, 18.1 × 10.9 μm. The Stieda body is knob-like to half-moon-shaped and sub-Stieda is rounded. Sporocyst residuum is present, composed of scattered spherules of different sizes. Sporozoites are vermiform, with refractile bodies and nucleus. Molecular analysis at the COI gene exhibited similarity of 97% with Isospora serinuse Yang, Brice, Elliot et Ryan, 2015 from island canaries Serinus canaria (Linnaeus, 1758), and Isospora spp. from great tits Parus major (Linnaeus, 1758) and European robins Erithacus rubecula (Linnaeus, 1758).
Conclusion: Based on the morphological and molecular features, I. oliveirai is considered as new to science and the first coccidian species recorded from Tityridae.