Morphological and molecular characterization of Eimeria purpureicephali n. sp. (Apicomplexa:Eimeriidae) in a red-capped parrot (Purpureicephalus spurius, Kuhl, 1820) in Western Australia

摘要

A new Eimeria species is described from a red-capped parrot (Purpureicephalus spurius). Sporulated oocysts (n = 31) were spherical to subspherical, with a rough bilayered oocyst wall 0.8 @mm thick. Oocysts measured 24.0 x 22.8 (20.4-26.4 x 18.3-25.9) @mm, oocyst length/width ratio, 1.10. Oocyst residuum, polar granule and micropyle were absent. Sporocysts are elongate-ovoid, 11.0 x 7.3 (12.7-9.2 x 7.9-6.6) @mm, sporocyst length/width ratio, 1.51 (1.33-1.71). The thin convex Stieda body and indistinct substieda bodies were present and the sporocyst residuum was composed of numerous small granules less than 1.0 @mm in diameter dispersed randomly. Each sporocyst contained 2 sausage-shaped sporozoites in head-to-tail arrangement. The sporozoite nuclei were located centrally surrounded by refractile bodies. Molecular analysis was conducted at two loci; the 18S ribosomal RNA gene and the cytochrome c oxidase subunit I gene. At the18S locus, the new isolate shared 99.0% genetic similarity with Eimeria dispersa and Eimeria innocua from the turkey. At the cytochrome c oxidase subunit I gene locus, this new isolate was most closely related to E. dispersa and E. innocua, presented 99.0% and 98.0% genetic similarity, respectively. This new isolate and E. dispersa grouped together in the same clade. Based on the morphological and molecular data, this isolate is a new species of coccidian parasite, which is named Eimeria purpureicephali n. sp. after its host, the red-capped parrot (Purpureicephalus spurius).