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(Fig. 1B). The UV exposure turns the whitish spots into a sparkling gold set of patches across the body, which were particularly contrasted in males. Although the snout region shows somehow a goldish pattern, the most visible spots begin on the head with the typical U-shaped spot behind the eyes and jugal bone. The overall pattern is consistent across the dorsum and shows a longitudinal striping with different shades. Some patches were also observed on the fore and hindlimbs, whereas the tail pattern shows circular motifs with GDE concentrated on its edges, following a more striped drawing. The flanks did not show any evident response, acting as a demarcation line running across the body. The unique analysed juvenile (total length< 70 mm) showed only a bone-based visible response, on its cranial bones and legs. So far, we could not state whether there is any inter-sexual difference for GDE, although a significant difference is visible among adults, juveniles, and some adult females. Finally, GDE was not visible in the only ethanol-fixed adult male specimen housed in the herpetological collection of the Museo Regionale di Scienze Naturali, Torino (catalogue number: MRSN R3838; Fig. 2). This agrees with Prötzel et al.(2021), who did not report any dermal fluorescence in preserved specimens of P. rangei.

Unfortunately, since no tissue samples were available, we could not perform histological spectroscopy to measure the quantum yield. For such reason, we also could not unequivocally confirm whether the observed UV-induced response in P. microphyllus is a true biofluorescence. Notwithstanding, we believe that such an observation …