Isospora troglodytes n. sp. (Apicomplexa: Eimeriidae), a new coccidian species from wrens of Costa Rica.

Nineteen (91%) of 21 rufous-and-white wrens (Thryothorus rufalbus) and five (71%) of seven plain wrens (Cantorchilus modestus) sampled from Costa Rica were positive for a new species of Isospora. Oocysts have a thin, smooth, double, colorless wall and measure 20.1 ± 1.4 × 23.4 ± 1.5 µm (18-24 × 20-26 µm) with an average length-width ratio of 1.2 µm. Sporocysts are ovoid, measure 9.5 ± 0.9 × 15.5 ± 1.1 µm (7-12 × 12-18 µm) with an average length-width ratio of 1.6 µm. A nipple-like steida body continuous with the sporocyst wall and a prominent oval-shaped substeida body are present. In addition to the four sporozoites, a single compact sporocyst residuum was present in each sporocyst. This is the first description of an Isospora species from the family Troglodytidae and the first report of Isospora from the rufous-and-white wren and plain wren.

A new Isospora species of passerines in the family Turdidae from Costa Rica.

Seven thrush species (Turdidae) from Costa Rica were examined for intestinal parasites; 21 of the 84 (25%) birds sampled were positive for a new species of Isospora. Oocysts of Isospora zorzali n. sp. have thin, smooth, double, and colorless walls; they measure 19.7 ± 1.5 µm × 18.6 ± 1.4 µm (16-24 µm × 15-21 µm), with an average length-width ratio of 1.1 µm. Sporocysts are ovoid, measure 8.5 ± 1.1 µm × 14.5 ± 1.7 µm (7-11 µm × 11-18 µm) with an average length-width ratio of 1.7 µm. A nipple-like stieda body continuous with the sporocyst wall is present, but no substieda body was observed. A sporocyst residuum consisting of large equal sized granules was observed either clumped together or diffusely. The sporocysts fill the entire oocysts with little to no open space observed. This is the first report of Isospora species from any of the sampled host species and also the first report from any species of thrush in Costa Rica.

New species of Isospora from the blue-crowned motmot (Momotus momota) from Costa Rica.

Two (33.3%) of 6 blue-crowned motmots (Momotus momota) sampled from Costa Rica were positive for a new species of Isospora. Oocysts of Isospora momotana n. sp. have a double, thick, yellow to orange, 2.3 microm +/- 0.5 microm (2-3 microm) wall, contain 1 to 3 globular polar granules (1-4 microm), are ovoid with heavy pitting on the outer surface, and measure 29.4 +/- 2.3 x 27.5 +/- 2.3 (25-33 x 23-31) with an average length:width ratio of 1.1 (1.0-1.35). Sporocysts are ovoid, contain a residuum composed of large, equal-sized granules, and measure 19.4 +/- 1.3 x 12.2 +/- 1.1 (16-22 x 10-14) with an average length:width ratio of 1.6 (1.2-1.91). A small rounded stieda body, continuous with the sporocyst wall, and a prominent triangular substieda body are present. A second Isospora species was observed in 1 bird, but because only a few oocysts were present, a full description is not provided. This is the first report of coccidia from a motmot (Momotidae) and only the third Ispospora species described from the Coraciiformes.