Xanthophores

Xanthophores are pigment cells that form part of the pigment cell system in vertebrates, most notably in fish, amphibians, and some reptiles. They are a type of chromatophore derived from neural crest cells during development and contribute to yellow to orange coloration on the skin or scales. In many species, xanthophores interact with other chromatophore types to create complex color patterns.

Xanthophores contain pigments such as carotenoids and pteridines. Carotenoids are typically acquired from the diet and stored in pigment granules, while pteridines are synthesized by the cells. The yellow hue of xanthophores results from the specific combination and concentration of these pigments, and the overall color can be influenced by the arrangement of pigment granules and by overlay from other chromatophores.

In fishes, xanthophores reside mainly in the dermis, often in layers with or beneath iridophores and melanophores that contribute to structural or darker colors. Amphibians and some reptiles also have xanthophores in the dermal layers. The density and distribution of xanthophores can vary between species and individuals, influencing distinctive color patterns.

Xanthophore coloration can change in response to hormonal and neural signals. Pigment granules may disperse or aggregate within the cells, producing rapid or gradual shifts in visible color. Diet, environmental conditions, and physiological state can affect xanthophore pigmentation, contributing to camouflage, signaling, and species- or sex-specific patterning.