Cutaneous properties of the Green and Golden Bell Frog Litoria aurea

We measured rates of evaporative water loss (EWL) in Litoria aurea at 25, 30, 33, and 35°C. There was a substantial rise in EWL over this range of temperatures, averaging 12.3 and 23.5 mg g-1 h-1 at 25 and 35°C, respectively. The rise in EWL over this temperature interval was associated with a corresponding drop in cutaneous resistance to water vapour flux (rc) which steadily declined from 6.9 to 3.5 s cm-1. The average highest rc measured for these eight frogs was 7 s cm-1 which places this species amongst frogs considered to have moderately waterproof skins. We also quantified the spectral reflectance of L aurea dorsal skin at wavelengths between 280 and 900 nm, The skin had a peak at 550 nm which was expected for a green frog, but lacked the abrupt rise in reflectance at about 700 nm found in green leaves and some other species of green, leaf-sitting Litoria species. The absence of high near-infra-red reflectivity in L aurea is attributed to its retention of melanin as a darkening pigment instead of pt...