RESUMO
Coccidian protozoan species recorded from flycatchers are few, but they have been described with a certain frequency in recent years. In this context, the present study describes a new Isospora sp. from sepia-capped flycatchers Leptopogon amaurocephalus Tschudi, 1846 captured in the Itatiaia National Park and in a reforestation area which is about 60 km away from the park boundaries, in addition to providing a molecular identification via sequencing of the mitochondrial cytochrome c oxidase subunit 1 gene. Isospora leptopogoni n. sp. has oöcysts that are subspheroidal to ovoidal, measuring on average 22.0 × 19.7 µm, with a smooth, bi-layered wall, c.1.7 µm thick. The micropyle is delicate or inconspicuous. Oöcyst residuum is absent, but one to three polar granules are present. Sporocysts are lemon-shaped, measuring on average 14.7 × 9.3 µm, with a knob-like Stieda body and a rectangular to rounded sub-Stieda body. Sporocyst residuum is present, consisting of compactly bounded granules. Sporozoites are vermiform, with refractile bodies and nucleus. Isospora leptopogoni is different from other Isospora spp. mainly due to its lemon-shaped sporocysts, the presence of micropyle and details of Stieda and sub-Stieda bodies. Phylogenetic analysis placed I. leptopogoni close to other Isospora spp. recorded from phylogenetically related hosts and from the same biogeographic region. Finally, the recurrent finding of this coccidian species in the same L. amaurocephalus specimen in a specific locality in the Itatiaia National Park suggests that the dispersion of I. leptopogoni needs continuous transmissions between susceptible passerines as the area of movement of each L. amaurocephalus specimen appears to be quite small.
Assuntos
Isospora , Passeriformes , Sepia , Aves Canoras , Animais , Isospora/genética , Oocistos , Filogenia , América do Sul , Especificidade da EspécieRESUMO
BACKGROUND: The gnateaters Conopophaga spp. are insectivorous passerines commonly observed in high and humid forests, where they remain lodged in thin branches and, sometimes, they fly to the ground to catch insects. The insectivorous feeding habit is related to low prevalence and density of coccidians in passerines; however, several coccidian species are recorded for families of insectivorous passerines. PURPOSE: This study aimed to examine the feces from gnateaters Conopophaga spp. captured in the municipality of Barra Mansa and in the Itatiaia National Park, State of Rio de Janeiro, Southeastern Brazil, to determine what coccidian parasites were present. METHODS: Nine gnateaters were 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 (cox1) gene, with phylogenetic reconstructions based on the neighbor-joining and maximum likelihood analysis. RESULTS: Four Conopophaga spp. were positive for oocysts. An Isospora sp. considered as new to science is described and identified from Conopophaga melanops (Vieillot, 1818) and Conopophaga lineata (Wied, 1831). Isospora borbai n. sp. has oocysts that are subspheroidal, 17-22 × 15-22 (20.2 × 19.1) µm, with rough, bilayered wall, c.1.7 µm thick. Micropyle present, but without micropyle cap. Oocyst residuum absent, but one or two polar granules are present. Sporocysts are ellipsoidal, 12-15 × 8-11 (14.1 × 9.1) µm. The Stieda body is knob-like to half-moon-shaped and sub-Stieda body is rounded. Sporocyst residuum is present, composed of scattered spherules of different sizes. Sporozoites are vermiform with refractile body and nucleus. Molecular analysis at the cox1 gene exhibited similarity greater than 99% with Isospora spp. isolates from other Neotropical passerine birds. CONCLUSION: Based on the morphological and molecular features, I. borbai is considered as new to science and the first coccidian species recorded from Conopophagidae.
