New Guinea is poorly studied, but in 2002, some 75,000 individuals were exported from Indonesia as part of the pet trade, and this may impact populations in some locations. The frog is present in a number of protected areas in New Guinea, and it has been successfully bred in some Australian zoos. Overall, the main threat to this species is the potential for a widespread disease epidemic. Use in research Although frogs have lungs, they absorb oxygen through their skin; for this to occur efficiently, the skin must be moist. A disadvantage of moist skin is that pathogens such as molds and bacteria can thrive on it, increasing the chance of infection. To counteract this, frogs secrete peptides that destroy these pathogens. The secretion from the paratoid gland of the green tree frog contains 25 caerins, a group of peptides with antibacterial and antiviral properties. The caerins produced by frogs of this species from different geographical localities have subtle but reproducible differences. The secretions also contain caeruleins, which have the same physiological effects as CCK-8, a digestive hormone and hunger suppressant. These caeruleins now have a number of clinical applications. Several peptides from the skin secretions of the green tree frog have been found to destroy HIV without harming healthy T cells. The fungus Batrachochytrium dendrobatidis, the causal agent of chytridiomycosis, is causing declines in many species of amphibians, but the secretions produced by the green tree frog and certain other Australian species of frog (Litoria chloris and Litoria genimaculata) are protective against this fungus. The peptides inhibit the growth of the fungus in vitro and these frog species are believed not to be in decline. Green tree frogs are sometimes used as model animals in research. The structure of their toe pads was used to investigate the microstructure and properties of the epithelium that allows the animals to adhere to wet surfaces. References Bibliography Egerton, L. ed. (2005). Encyclopedia of Australian wildlife. Reader's Digest External links Amphibians of New Guinea Amphibians of New South Wales Amphibians of Queensland Amphibians of South Australia Amphibians of the Northern Territory Amphibians of Western Australia Amphibians described in 1790 Litoria Frogs of Australia Taxa named by John White (surgeon)