Caryospora peneireiroi n. sp. (Apicomplexa: Eimeriidae) in the common kestrel, Falco tinnunculus (Falconiformes: Falconidae), in mainland Portugal.

The common kestrel Falco tinnunculus Linnaeus, 1758, is a widespread raptor, native in Europe, Asia and Africa, and vagrant in the Americas. In the current work, 27 fecal samples were collected from common kestrels kept in the Lisbon Center for Wild Animal Recovery, located at Monsanto Forest Park, Lisbon, Portugal. Five (19%) of them were found to be passing an undescribed species of Caryospora in their feces. The oocysts of Caryospora peneireiroi n. sp. were ellipsoidal with a bilayered wall and measured 47.1 × 37.6 µm with a shape index of 1.25. No micropyle, oocyst residuum or polar granule was present. The sporocysts were subspherical, measuring 25.1 × 24.3 µm. Stieda, sub-Stieda and para-Stieda bodies were absent. The sporocyst residuum was composed of many homogenous globules scattered throughout the periphery of the sporocyst. This is the fourth caryosporan species reported from F. tinnunculus.