Disease conditions and subclinical infections of the platypus (Ornithorhynchus anatinus)

Abstract

Before the arrival of European settlers in Australia, the platypus, Ornithorhynchus anatinus , probably suffered from little disease. Among other things, European settlement has involved substantial environmental perturbation, introduction of large predators, introduction of motor vehicles and translocation of potential pathogens. As a result, platypuses are now killed by motor vehicles, dogs, foxes and discarded plastic litter. Information programmes targeting appropriate segments of the public would help reduce these unnecessary deaths. The enigmatic disease, ulcerative mycosis, caused by Mucor amphibiorum , has been the subject of scientific investigation in Tasmania for the past 15 years. The apparent recent acceleration in its spread has sounded a warning and more intensive investigation is warranted. The possibility that this pathogen has been translocated from subtropical to temperate Tasmania, Australia, with green tree frogs in banana shipments further emphasizes the role of humans in threatening the welfare of the platypus. Recommendations are made in relation to appropriate measures that could be taken to ameliorate disease and trauma in this species.

Hematologic, Plasma Biochemical, and Other Indicators of the Health of Tasmanian Platypuses (Ornithorhynchus Anatinus): Predictors of Mucormycosis

“…The disease was first detected in platypuses from the Elizabeth River in Tasmania's northern midlands in 1982 (Munday and Peel, 1983). The fungal pathogen responsible was identified as Mucor amphibiorum (Obendorf et al, 1993).…”

“…All animals were individually identified on the first capture with a passive integrated transponder (PIT) tag (Trovan, Hessle, East Yorkshire, UK or Allflex, Capalaba, Queensland, Australia) inserted subcutaneously between the scapulae. Visual health assessments were made by physical examination of each captured individual to determine the presence of ulcers, granulomas, wounds, or other abnormalities (Munday and Peel, 1983;Connolly et al, 1998). Individuals were considered to be clinically healthy when no external injuries or lesions were observed and there was no evidence of disease or emaciation.…”

“…Although M. amphibiorum can cause mortality in a variety of amphibian species on mainland Australia (Frank, 1975;Speare et al, 1994), only platypuses appear to be affected by the fungus in Tasmania. The pathogen may have been introduced to Tasmania via infected frogs or toads illegally imported as pets or transported with fruit shipments from mainland Australia (Munday et al, 1998).…”

Novel use of in-stream microchip readers to monitor wild platypuses.

“…Gust and Handasyde (1995) and Bethge et al (2003) found a mean foraging durations of ~10 hr/day and 11.5 hr/day respectively. During foraging trips, platypuses have been observed to move distances of a few hundred metres to several kilometres along rivers and/or streams and have been known to move over land to avoid obstructions such as waterfalls, culverts or meanders in rivers (Serena 1994;Gardner and Serena 1995;Gust and Handasyde 1995;Munday et al 1998;Mooney and Spencer 1999). In this study, we investigate the novel use of instream microchip readers as a remote, long-term and relatively non-labour intensive method of monitoring microchipped wild platypuses as they move along waterways during foraging.…”

Novel genotypes of Trypanosoma binneyi from wild platypuses (Ornithorhynchus anatinus) and identification of a leech as a potential vector

“…More recently, 536 a study of native Australian mammals identified Ixodes australiensis 537 as the vector for Trypanosoma copemani (Austen et al, 2011). PB70 PB09 PB72 PB74 PB76 PB81 PB82 PB85 PB90 PTL57 PB52 PB89 PB78 PB94 PB77 PB88 PB80 PB75 (Anderson and Ayala, 1968), and a midge 546 (Corethrella wirthi) one from a treefrog (Hyla cinerea) (Johnson 547 et al, 1993) (reviewed by (Hamilton et al, 2004) as already suggested (Munday et al, 1998); thus, until further 551 studies are conducted, this debated theory cannot be refuted.…”