The ultrastructure of some endogenous stages of the coccidian Eimeria boveroi Carini & Pinto, 1926 in the gut epithelial cells of the gecko Hemidactylus mabouia from Brazil

The endogenous development, described by light and electron microscopy, of Eimeria jamescooki sp. n. (Apicomplexa: Eimeriidae) from the skink Cryptoblepharus virgatus

Eimeria jamescooki sp. n. was recovered from the skink Cryptoblepharus virgatus (Garman) found on the grounds of James Cook University, Townsville (type locality), North Queensland, Australia. Oocysts were 17.5-25.0 (22.1 +/- 1.9) x 15-22.5 (17.7 +/- 1.6) microm and sporocysts 6.25-10.0 (7.9 +/- 1.15) x 3.75-6.25 (5.3 +/- 1.0) microm in size. Endogenous stages are described from histological material examined by light microscope and by transmission electron microscope. Both merogony stages and gamonts were found to develop in the cytoplasm of the anterior gut mucosal epithelium. Meront progeny were comprised of 10 to 21 merozoites. Premature macrogamonts were elongate; some host cells contained two elongate macrogamonts. Unique to the presently described species were the Golgi "plaques" and an enclosure of tubuli. Mature macrogamonts and young oocysts ranged in size from 14 x 7 to 21 x 11 microm and contained two types of wall-forming bodies, canaliculi and amylopectin granules. Differentiating microgamonts conformed in fine structure with that observed in other eimerians. Their sizes increased from 15.4 x 4.2 to 28 x 8.4 microm while dividing to over 70 nuclei, which formed a corresponding yield of microgametes.

The phylogeny of Goussia and Choleoeimeria (Apicomplexa; Eimeriorina) and the evolution of excystation structures in coccidia

The phylogenetic relationships of Goussia janae and Choleoeimeria sp. were analyzed using the small subunit ribosomal RNA gene (SSU rDNA). This is a first attempt to study the molecular phylogeny of coccidian genera parasitizing strictly poikilotherm hosts. The biliary Eimeria-like coccidia of reptiles classified into the genus Choleoeimeria form a sister clade to the family Eimeriidae, which confirms the separate generic status of the genus Choleoeimeria. The position of Goussia is less robustly resolved, since it forms a trichotomy with the Eimeriidae and Sarcocystidae, or alternatively constitutes the earliest branch of the coccidian lineage. Morphological similarities, namely the extracytoplasmic location of the endogenous stages, and the presence of sutures in the sporocyst wall are discussed in the context of the traditional classification of eimeriids. In contrast to the morphology-based systematics, the monophyly of Goussia and Choleoeimeria is not supported by the SSU rDNA data.

Ultrastructural study of meronts and gamonts of Choleoeimeria rochalimai (Apicomplexa: Eimeriidae) developing in the gall bladder of the gecko Hemidactylus mabouia from Brazil

Endogenous development of Choleoeimeria rochalimai (Carini et Pinto, 1926) Lainson et Paperna, 1999 in the gall bladder of Hemidactylus mabouia (Moreau de Jonnes, 1818) from Belém, Brazil is reported at the fine structural level. Meronts and gamonts develop in the epithelial cells of the gall bladder. Infected cells become enlarged and displaced above the epithelial layer. Developing merozoites, dividing meronts and succession of developing microgamonts from initial nuclear division up to final microgamete differentiation are described. In addition towall forming bodies, mature macrogamonts possess a large inclusion or cisterna with fine granular contents.