Isospora anthochaerae n. sp. (Apicomplexa: Eimeriidae) from a Red wattlebird (Anthochaera carunculata) (Passeriformes: Meliphagidae) in Western Australia

Abstract

A new species, Isospora anthochaerae n. sp. is described from a Red wattlebird (Anthochaera carunculata). Sporulated oocysts (n=37) are subspherical, with smooth colourless to pale brown bilayered oocyst wall, 0.8μm thick (outer layer 0·6μm, inner 0.2μm thick). Oocyst with 2 spheroidal to subspheroidal sporocysts. Oocyst length, 23.4μm (20.0–26.0); oocyst width, 20.7μm (19.0–22.0); oocyst length/width (L/W) ratio, 1.1. Micropyle, oocyst residuum and polar granule are absent. Sporocysts with compact sporocyst residuum and 4 sporozoites. Sporocyst length, 14.5μm; sporocyst width, 10.1μm sporocyst L/W ratio, 1.4. Molecular analysis was conducted at four loci; the ribosomal internal transcribed spacer (ITS), the 18S and 28S ribosomal RNA and the mitochondrial cytochrome oxidase gene (COI). At the COI locus, I. anthochaerae n. sp. exhibited 98.5% similarity to Isospora lesouefi from a Regent honeyeater (Xanthomyza phrygia) and 98% similarity with an Isospora sp. (iSAT5) from a blackcap (Sylvia atricapilla). Based on morphological and molecular data, this isolate is a new species of coccidian parasite that to date has only been found in Red wattlebirds.