Morphological and molecular characterization of Choleoeimeria pogonae n. sp. coccidian parasite (Apicomplexa: Eimeriidae, 1989, Paperna and Landsberg) in a western bearded dragon (Pogona minor minor).

ABSTRACT

A new species, Choleoeimeria pogonae n. sp. is described from a Western bearded dragon (Pogona minor minor) in Western Australia. Sporulated oocysts (n = 48) were cylindroidal in shape. Oocyst length, 27.0 (26.0-28.3) µm, oocyst width, 15.2 (14.0-16.5) µm, oocyst length/width ratio (L/W) 1.8 (1.6-1.9), each with 4 sporocysts (Eimeria-like) and a polar granule, but lacking a micropyle and oocyst residuum. Sporocysts are ovoidal in shape, sporocyst length, 10.0 (9.0-11.0) µm, sporocyst width 8.5 (7.0-9.5) µm, sporocyst L/W ratio, 1.2 (1.1-1.3). Stieda, substieda and parasubstieda bodies were all absent. Molecular analysis was conducted at the 18S rRNA and cytochrome c oxidase I (COI) loci. Phylogenetic analysis of 18S sequences revealed that C. pogonae n. sp. grouped together with another four Choleoeimeria spp. and exhibited 99.1%-99.4% genetic similarity. At the COI locus, C. pogonae n. sp. was in an independent clade and had the highest similarity (80.4%) to Eimeria cf. mivati from a chicken (Gallus gallus domesticus). According to the morphological and molecular data, this isolate is a new species of coccidian parasite. This study further supports the taxonomy of Choleoeimeria spp. as a new genus based on molecular phylogenetic analysis.