A diet may be the origin of the yellow coloration of the skin of some reptiles, similar to what happens with flamingos, whose pink hue results from pigments present in their diet. A study by Australian researchers identified riboflavin, or vitamin B2, as responsible for part of the yellow pigmentation observed in two species of lizards and in one species of snake.
The investigation, published in Royal Society Open Science, used mass spectrometry to analyze the pigments present in the animals’ skin. The researchers found that the yellowest areas of skin showed higher concentrations of riboflavin, and that this vitamin was able to produce a yellow coloration even in the absence of other pigments.
Riboflavin is obtained through the diet and plays important roles in the body, notably in cellular metabolism and growth. Unlike some pigments that can be produced by the body itself, it must be acquired through the diet.
This characteristic brings the pigmentation of the studied reptiles closer to the phenomenon observed in flamingos. These birds obtain carotenoids through their diet, which are the source of their well-known pink plumage. The intensity of this coloration may be related to the amount of pigments available in the diet.
The researchers suggest that something similar could happen in reptiles: a more intense yellow coloration could act as a signal of the animal’s condition, since it depends on the availability of riboflavin in the diet, and this vitamin is important for several biological functions.
However, this possibility is presented by the authors as a hypothesis. The study shows the relationship between riboflavin concentration and the yellow coloration of the skin, but does not establish that the intensity of the color is, in itself, a direct indicator of the animals’ health.
Thus, the discovery adds riboflavin to the list of diet-derived pigments capable of contributing to the coloration of animals and shows how diet can influence visible traits far beyond nutrition.
