chameleonism

Chameleonism refers to the ability of an organism to change its color. While most commonly associated with chameleons, this phenomenon is also observed in other animals such as cephalopods like octopuses and squid, as well as some fish and amphibians. The primary functions of color change vary depending on the species and its environment.

In chameleons, color change is primarily used for thermoregulation, communication with other chameleons, and camouflage. They can darken their skin to absorb more heat or lighten it to reflect sunlight. They also use color to signal aggression, mating readiness, or stress. This remarkable ability is achieved through specialized cells in their skin called chromatophores, which contain pigments. By expanding or contracting these cells, the animal can alter the amount and distribution of pigment, thereby changing its visible color.

In aquatic animals like octopuses, color change is crucial for both camouflage and communication. They can rapidly alter their skin texture and color to blend seamlessly with their surroundings, evading predators or surprising prey. Some cephalopods also use intricate patterns of color change to communicate with each other. Fish, too, employ color change for camouflage, mating displays, and as a warning signal. The underlying mechanisms can involve chromatophores, iridophores (cells that reflect light), and leucophores (cells that scatter light). The speed and complexity of color change can differ significantly across species.