Three new species of Isospora Schneider, 1881 (Apicomplexa: Eimeriidae) from the lesser seed-finch, Oryzoborus angolensis (Passeriformes: Emberizidae) from Brazil

Three new coccidian (Apicomplexa: Eimeriidae) species are reported from the lesser seed-finch, Oryzoborus angolensis from Brazil. Sporulated oocysts of Isospora curio n. sp. are spherical to subspherical; 24.6 x 23.6 (22-26 x 22-25) microm, shape-index (SI, length/width) of 1.04 (1.00-1.15). Oocyst wall is bilayerd, approximately 1.5 microm thick, smooth and colourless. Micropyle and oocyst residuum are absent. The sporocysts are ovoid, 13.2 x 10.9 (15-17 x 10-13) microm, SI = 1.56 (1.42-1.71), with a small Stieda body and residuum composed of numerous granules scattered among the sporozoites. Sporozoites are elongated and posses a smooth surface and two distinct refractile bodies. Oocysts of Isospora braziliensis n. sp. are spherical to subspherical, 17.8 x 16.9 (16-19 x 16-18) microm, with a shape-index of 1.06 (1.00-1.12) and a smooth, single-layered wall approximately 1 microm thick. A micropyle, oocyst residuum and polar granules are absent. Sporocysts are ellipsoid and slightly asymmetric, 13.2 x 10.8 (12-14 x 9-12) microm, SI = 1.48 (1.34-1.61). Each sporocyst contains a barely visible Stieda body and a residuum composed numerous of granules. Sporozoites are elongated and each of them contains two distinct refractile bodies. Oocysts of Isospora paranaensis n. sp. are subspherical to broadly ellipsoid 24.3 x 19.8 (22-26 x 18-22) microm, SI = 1.22 (1.15-1.38) with smooth single-layered wall approximately 1.5 microm thick. A micropyle and oocyst residuum are absent, but one distinct ellipsoid polar granule (2.5-3.5 x 1.5-2.5 microm) is present. Sporocyst are ovoid, 15.7 x 10.1 (14-18 x 8-12) microm, SI = 1.46 (1.31-1.72), with distinct Stieda and sub-Stieda bodies. Each sporocyst contains a spherical sporocyst residuum, 4 microm in diameter All described isosporan species represent a possible cause of acute coccidiosis for O. angolensis in captivity.

The lesser seed-finch Oryzoborus angolensis (Linnaeus, 1766) (Passeriformes: Emberizidae) is a bird distributed in open woodland, savanna, bushes, and shrubs in forest edge of Latin America. They are found from North of the Lesser Antilles through Venezuela, Brazil, and Bolivia to South Argentina (Sick 1993). The lesser seedfinches are highly coveted as pet birds and are considered to be among the noblest singing birds. This feature has made this species one of the most highly prized songbirds in Brazil and many birds are bred in captivity. These finches are also frequently trapped from the wild and, consequently, wild lesser seed-finch populations have declined. No species of Isospora have previously been described in emberizid birds of the genus Oryzoborus. The present study provides descriptions of three new species of Isospora from O. angolensis.

MATERIALS AND METHODS
A total of 675 O. angolensis were examined in this study. The birds originated from 48 private aviaries localized in the state of Mato Grosso do Sul, Brazil. They were reared in suspended cages and individual faecal samples were collected immediately upon defecation on tinfoil on the bottom of the cages at the different day-time. Faecal material was placed in vials containing 2.5% (w/v) potassium dichromate solution and shipped to the University of Veterinary and Pharmaceutical Sciences in Brno for follow-up examination. Faecal samples were 3-8 weeks old when screened for coccidia using flotation in Sheather's sugar solution (specific gravity 1.30). The sporulated oocysts were examined and photographed with an Olympus AX 70 microscope using Nomarski interference contrast optics (DIC). All measurements were made using a calibrated ocular micrometer and reported as means in micrometers (µm), followed by the range in parentheses.
Type locality -Material was isolated from faeces of captive birds in Mato Grosso do Sul.
Type locality -Material was isolated from faeces of captive birds in Mato Grosso do Sul.

Sporulation -Exogenous. Time required unknown.
Type material -Photo-syntypes deposited under the de- Etymology -The specific name is derived from the country of origin of the host.

Type locality -Material was isolated from faeces of captive birds in Mato Grosso do Sul.
Prevalence -1.77 %.
Site of infection -Unknown, oocysts recovered from faeces.

Sporulation -Exogenous. Time required unknown.
Type material -Photo-syntypes deposited under the depository number B 231 in the Department of Parasitology, University of Veterinary and Pharmaceutical Sciences Brno, Czech Republic.
Etymology -The specific name is derived from the State of Parana, Brazil.

DISCUSSION
To date, there are around 50 species of Isospora described from emberizids birds (http://www.ksu.edu/para-   sitology/worldcoccidia/PASSER01?, de Carvalho Filho et al. 2005). However, no named species have been reported from the genus Oryzoborus. We compared the three observed species of Isospora from O. angolensis with valid isosporans described from emberizids birds resident in South America or immigrating through this subcontinent and all were found to be different from all the presently described species. These are therefore, considered as new species.
The species most closely resembling I. curio n. sp. are I. formarum McQuistion and Capparella 1992, I. tiaris Ball and Daszak 1997, and I. sporophilae de Carvalho Filho, de Meireles, Ribeiro and Lopes 2005 Ball andDaszak 1997 andI. sporophilae de Carvalho Filho et al. 2005. However, I. paranaensis n. sp. tends to be broadly ellipsoid, compared with the subspherical oocysts of above mentioned species. In addition, I. paranaensis n. sp. differs from I. formarum in having a distinct polar gran-ule. The oocyst of I. tiaris differs from that of I. paranaensis n. sp. in its morphology, being larger and having morphological differences in the sub-Stieda body and sporocyst residuum. The sporocysts of I. paranaensis n. sp. show morphological differences in the presence of a sub-Stieda body, which is absent in those of I. sporophilae.
Based on all above mentioned morphological characteristics, together with host´s distribution in nature we consider the species described here to be new coccidian species from captive O. angolensis kept in Brazil.
In the present study, coprological examinations indicate a widespread exposure to coccidian parasites among O. angolensis in this country. Coccidian infection may be responsible for loss of weight, low reproduction and death in breeding groups of this songbird. Further research should determine the pathology of these coccidial infections in these birds.