Amphibian biofluorescent emission spectra. The peak emission wavelengths of the biofluorescent light emitted by salamanders, frogs (Ceratophrys cranwelli), and caecelians (Typhlonectes natans) are green to greenish-yellow. Biofluorescent emissions were measured with a FLAME spectrometer through a yellow long pass filter (500 nm) from either the dorsal (Ceratophrys, Ambystoma, Dicamptodon) or ventral surfaces (Typhlonectes, Amphiuma, Cynops, Icthyosaura), but we did not focus on any specific part of the anatomy (see Methods for further detail). Relative intensities of these biofluorescent emissions varied substantially across taxa. Pictured are white light images of T. natans and C. cranwelli above images of these species biofluorescing. Biofluorescence was imaged by exposing individuals to blue light (440–460 nm) and viewing them through a yellow long pass filter (500 nm).