Afternoon shedding of a new species of Isospora (Apicomplexa) in the endangered Regent Honeyeater (Xanthomyza phrygia)

• Published in: Parasitology 2011-05, Vol.138 (6), p.713-724
• Main Authors: MORIN-ADELINE, VICTORIA, VOGELNEST, LARRY, DHAND, NAVNEET K., SHIELS, MICHAEL, ANGUS, WARRICK, ŠLAPETA, JAN
• Format: Article
• Language: English
• Subjects: Animals; Animals, Zoo - parasitology; Apicomplexa; Australia; Aves; Biological and medical sciences; Bird Diseases - parasitology; Birds; Circadian Rhythm - physiology; Coccidiosis - parasitology; Coccidiosis - veterinary; Electron Transport Complex IV - genetics; Endangered & extinct species; Endangered Species; Feces - parasitology; Fundamental and applied biological sciences. Psychology; General aspects; General aspects and techniques. Study of several systematic groups. Models; Intestines - parasitology; Introduced species; Invertebrates; Isospora; Isospora - cytology; Isospora - genetics; Isospora - physiology; Linear Models; Medical screening; Molecular Sequence Data; National parks; Oocysts; Oocysts - cytology; Parasites; Passeriformes - parasitology; Protozoa; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution; Xanthomyza phrygia
• ISSN: 0031-1820; 1469-8161
• DOI: 10.1017/S0031182011000126

The Regent Honeyeater (Xanthomyza phyrigia) is an endangered Australian bird species. Breeding populations have been established at Australian zoos in support of re-introduction programmes. This species is the host of a new species of Isospora (Apicomplexa). Oocysts are spherical, 25·8 (22·5–28·75) by 23·8 (20–26·25) μm with a colourless to pale yellow smooth wall undergoing rapid exogenous sporulation, 90% sporulated oocysts in 8 h at 20°C. Each oocyst contains 1 polar granule. Sporocysts are ovoid, 18·67 (17–19) by 9·49 (9–10) μm with a flat Stieda body and spherical substieda body devoid of a hyaline body. The asexual stages and sexual phase is within the enterocytes of the duodenum and jejunum. Faeces collected in the morning (AM, n=84) and in the afternoon (PM, n=90) revealed significant diurnal periodicity in oocyst shedding; 21% (18 of 84) of the AM were positive with the mean of 499 oocysts.g−1 compared to the PM with 91% (82 of 90) bird faeces positive with the mean of 129 723 oocysts.g−1. Therefore, parasite checks for these birds should be carried out in the afternoon to obtain an accurate result. The ecological significance of the high parasite burden in captive birds requires further investigation and comparison to the wild counterparts.