Tuatara Research: Hunting for Brown Spots

The threat of Paranannizziopsis Australasiensis to New Zealand reptiles

Last week, veterinarian Rebecca Webster sampled 40 tuatara in ZEALANDIA as part of her research project investigating a recently discovered fungal disease of tuatara - Paranannizziopsis australasiensis (PA).

The detection of this disease is of concern to wild and captive population health and has resulted in a temporary cessation of tuatara breed for release programs. The origin of these infections and the prevalence of this organism in New Zealand is currently unknown. 

Infections result in dermatitis, starting as flaky brown discoloured skin and can progress to deep ulceration of the skin and infection in the muscle. It is usually seen on the abdomen, tail and under the chin. Fungi of this genera are thought to act as primary pathogens in reptiles, and have caused wide spread disease and death in wild snake populations across the USA and in bearded dragons in the pet industry.

Lesions have been reported in tuatara at multiple captive facilities in New Zealand, but lack of veterinary assessment and, until recently, inadequate diagnostic capabilities has led to an inability to confirm the presence or absence of this fungal disease in these populations.

Rebecca’s research aims to investigate the epidemiology of PA in New Zealand wild and captive native reptiles. Skin samples are being collected from populations of tuatara, geckos and skinks to determine the distribution of the disease and range of species affected. Soil samples are being collected from burrows, basking areas and captive enclosures to determine the presence of the fungi within the environment.

ZEALANDIA contains a population of wild and captive tuatara, as well as many gecko and skink species, which are being used to assist with this research.

Testing in other regions is also being undertaken to better characterise the distribution of PA in New Zealand.

Rebecca Webster is a qualified veterinarian with 10 years of experience working with Australian and New Zealand wildlife. She is currently undertaking a Masters of veterinary science through Massey University in Palmerston North.