Thank you for visiting nature. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser or turn off compatibility mode in Internet Explorer. In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript. The phenomenon of fluorescence can be used by animals to change effective colouration or patterning, potentially to serve functions including intra- and interspecific signalling.
Initially believed to be restricted to marine animals, fluorescent colours are now being described in an increasing number of terrestrial species. Here, we describe unique, highly fluorescent patterns in two species of pumpkin toadlets Brachycephalus ephippium and B. We establish that the origin of the fluorescence lies in the dermal bone of the head and back, visible through a particularly thin skin.
Luminescence induced by absorption of photons, i. Fluorescence is a particular case of photoluminescence occurring when photons in the short wavelength range, such as ultra-violet UV , are absorbed by a molecule bearing a fluorophore and re-emitted at longer wavelengths. In fluorescence, the electronic energy transition responsible for the emission does not change in electron spin, in contrast with the electronic energy transition occurring in phosphorescence.
Among terrestrial species, fluorescence has recently been described in birds 1 , spiders 2 , frogs 3 and chameleons 4. Depending on the visual range and sensitivity of the observer, fluorescence may increase overall conspicuousness of an individual against the background 5 , serve as camouflage 6 or provide additional information, if the fluorescent patterns differ from the colour patterns visible under non-UV light but see 7 for an example of fluorescent patterns not contributing to visual signals produced by toxic butterflies.
Fluorescent patches in parrots and spiders have been shown to play a role in sexual communication 1 , 2. Most compounds generating fluorescence have been found in external tissues, such as the cuticle of some invertebrates spiders 2 , shrimps 8 , scorpions 9 , the feathers of some parrots 1 , and the skin of fishes 5 , 10 , 11 , a marine turtle 12 and certain frogs 3 , Externally-visible fluorescent bone has been recently described in chameleons 4 , but never before in any other vertebrates.
