Isospora tiedetopetei n. sp. (Chromista: Apicomplexa: Eimeriidae) from black-goggled tanagers Trichothraupis melanops (Vieillot, 1818) (Passeriformes: Thraupidae: Tachyphoninae) in South America.

Abstract

Black-goggled tanagers Trichothraupis melanops (Vieillot, 1818) are passerine birds commonly observed in the Brazilian Atlantic Forest, Argentina and Paraguay. Tanagers are among the passerines with the highest prevalence and density of coccidian parasites, mainly due to their frugivorous feeding habits that favor fecal-oral transmission. In this context, the current study identifies a new species of Isospora Schneider, 1881 parasitizing black-goggled tanagers captured in the Itatiaia National Park, a protected area with a high degree of vulnerability in Southeastern Brazil. The oocysts of Isospora tiedetopetei Almeida-Berto & Berto n. sp. are subspheroidal to ovoidal, measuring on average 24 by 23 μm. Micropyle is absent. Oocyst residuum absent, but comma-like and splinter-like polar granules are present. Sporocysts are ovoidal to slightly pear-shaped, measuring on average 16 by 11 μm. Stieda and sub-Stieda bodies are present. Sporocyst residuum is present among the vermiform sporozoites, which have striations, refractile body and nucleus. This morphology was different from the other Isospora spp. recorded in the same subfamily as the host. Molecular identification was targeted by the amplification and sequencing of four loci of the mitochondrial genome and the small subunit ribosomal RNA (18S) gene. In molecular and phylogenetic analyses of concatenated sequences of 5 fragments, I. tiedetopetei n. sp. sat in monophyly and/or had high similarities with Isospora spp. from passerines. Finally, based on the morphological and molecular analyses of the oocysts recovered from black-goggled tanagers T. melanops in the current study, I. tiedetopetei n. sp. is established new to science, being the seventh species recorded in the host subfamily Tachyphoninae and the first to have a molecular characterization based on mitochondrial genes and the nuclear 18S gene.