Identification and genetic characterization of a novel species of Choleoeimeria Schneider, 1875 from a captive-bred bilby (Thylacomyidae; Macrotis lagotis) (Reid, 1837) in Western Australia.

A novel Eimeria sp. from a captive-bred bilby (Macrotis lagotis Reid, 1837) has been identified in Western Australia. The bilby was bred at the Kanyana Wildlife Rehabilitation Centre, Perth, as part of the National Bilby Recovery Plan. Oocysts (n = 31) irregular blunt ellipsoidal, 17-18 × 11-12 (17.2 × 11.3); length/width (L/W) ratio 1.4-1.5 (1.5). Wall bi-layered, 0.8-1.0 (0.9) thick, outer layer smooth, c.2/3 of total thickness. Micropyle barely discernible. Oocyst residuum is absent, but 2-3 small polar granules are present. Sporocysts (n = 31) ovoidal, 7-8 × 5-6 (7.8 × 5.7); L/W ratio 1.3-1.4 (1.4). Stieda, sub-Stieda and para-Stieda bodies absent or indiscernible; sporocyst residuum present, usually as an irregular body consisting of numerous granules that appear to be membrane-bound or sometimes diffuse among sporozoites. Sporozoites vermiform with a robust refractile body. Further molecular characterization was conducted on the sporulated oocysts. At the 18S locus, it sat in a large clade of the phylogenetic tree with two isolates of Eimeria angustus from quendas (Isoodon obesulus Shaw, 1797) and the Choleoeimeria spp. It shared the highest identity with E. angustus (KU248093) at 98.84%; at the COI gene locus, it was unique and most closely related to Choleoeimeria taggarti, which is hosted by another species of marsupial, the yellow-footed antechinus (Antechinus flavipes flavipes), with 90.58% genetic similarity. Based on morphological and molecular data, this isolate is a new species and named as Choleoeimeria yangi n. sp.

Eimeria spp. and Tyzzeria perniciosa Allen, 1936 (Apicomplexa: Eimeriidae) from a Pacific black duck, Anas superciliosa Gmelin (Aves: Anseriformes), in western Australia.

Four species of the Eimeriidae, Eimeria anatis Scholtyseck, 1955, Eimeria aythyae Farr, 1965, Eimeria krylovi Svanbaev & Rakhmatullina, 1967 and Tyzzeria perniciosa Allen, 1936, were morphologically identified from oöcysts recovered from a Pacific black duck, Anas superciliosa Gmelin. Additionally, genotypic characterization of E. anatis is provided via sequencing of the mitochondrial cytochrome c oxidase subunit 1 (cox1) and the small subunit ribosomal RNA (18S) genes. The four species are redescribed, providing additional morphological details. The validity of genera and coccidian species parasitizing birds of the order Anseriformes such as Wenyonella Hoare, 1933 and some Tyzzeria spp. are discussed. Molecular phylogenetic analyses for the cox1 and 18S rRNA genes resulted in monophylies of Eimeria spp. from Anseriformes which included the sequences obtained from E. anatis oöcysts.