In a recent study, German researchers observed a mechanism of biofluorescence. The animals we are talking about here are geckos, lizard-like reptiles. For a particular species, this characteristic would play a very important role in everyday life.
A “shiny” species of gecko!
Geckos represent a reptile infraorder whose species are found all over the world. Although they look like lizards, geckos actually group together many squamates (lizards / snakes). In the countries where these animals are present, the population appreciates them, because their favorite meal consists of harmful insects.
One species of gecko in particular was the subject of a publication in the journal Scientific reports on January 11, 2021. A team from the Zoological State Collection in Munich (Germany) was indeed interested in Pachydactylus rangei, a species endemic to the Namib desert in southern Africa. According to experts, this gecko is capable of biofluorescence. The authors of the study recall that this phenomenon is very widespread in the natural world. On the other hand, the animal in question is one of the only terrestrial vertebrates known to be capable of it. However, its shine is much more important than that previously observed in chameleons in 2018.
From yellow to “neon green”
Biofluorescence can result from several different mechanisms. In the case of some amphibians, it is induced by the circulation of chemical compounds in the lymphatic system. As for the gecko species Pachydactylus rangei, the shine comes from absorption of moonlight. Thus, it is triggered only at night and in their natural environment. More precisely, the phenomenon occurs at the level of the yellow marks present on the sides and around the eyes of the gecko. When these marks become fluorescent, their color changes to a “neon green”.
Of iridophore cells are at the origin of this process. Located under the translucent skin of the animal, they belong to the group of chromatophores and generate a certain color by reflecting light. They therefore absorb the light of the moon (excitation) before retransmitting it under a more stretched wavelength (emission light). But what is the use of biofluorescence in this species? According to the study authors, geckos can thus communicate with each other at night safe. Indeed, the location of their yellow marks makes the shine difficult to perceive by possible predators.