Coccidial dispersion across trans- and cis-Andean antbirds (Passeriformes: Thamnophilidae): Isospora sagittulae (Apicomplexa: Eimeriidae) from nonsympatric hosts

Abstract

Isospora sagittulae McQuistion and Capparella, 1992 (Protozoa: Apicomplexa: Eimeriidae) is reported from Whitethroated Antbirds (Gymnopithys salvini (Berlepsch, 1901)) and from Common Scale-backed Antbirds (Willisornis poecilinotus (Cabanis, 1847)), which are thamnophilid birds from the Brazilian Amazon. Its oocysts are ovoidal to ellipsoidal, 28.4 μm × 22.4 μm, with smooth, bilayered wall, 1.1 μm. Micropyle and oocyst residuum are absent, but one to three polar granules are present. Sporocysts are subspherical to ovoidal, 15.0 μm× 12.6 μm. Stieda body thin and flattened and substieda body triangular to round. Sporocyst residuum composed of scattered granules. Sporozoites with refractile body and nucleus. This coccidium was originally described from the Spotted Antbird (Hylophylax naevioides (Lafresnaye, 1847)), a trans-Andean antbird that is not sympatric with G. salvini and W. poecilinotus, which are cis-Andean antbirds from lowland Amazon forest; therefore, this current study presents some assumptions to explain the dispersion of I. sagittulae among antbird species.