First record of dermal fluorescence in the desert-adapted Stenodactylus and Trigonodactylus geckos

Even though steadily increasing, biofluorescence is a rarely documented phenomenon in vertebrates. Within geckos, only six species have been shown to produce fluorescence and only one case of dermal fluorescence has been reported. Here, we report on the discovery of dermal fluorescence in the Dune Sand Gecko (Stenodactylus doriae), the Eastern Sand Gecko (S. leptocosymbotes), and the Arabian Web-footed Sand Gecko (Trigonodactylus arabicus), three closely-related, nocturnal, desert-adapted Arabian geckos. We show that there are interspecific differences in fluorescent regions which might be linked to the habitat preference and behaviour of each species. Our results are in agreement with prior hypotheses suggesting that desert-adapted geckos might use dermal biofluorescence for conspecific signalling. With the present work, we expand the current knowledge on skin fluorescence in reptiles and provide new insights on fluorescence of desert-adapted geckos.