Can geckos change color in a way that resembles a chameleon’s dramatic shifts for camouflage or communication, altering their base coloration significantly and rapidly in response to environmental factors like temperature, light, or mood? Or is any perceived color change in geckos limited to subtle variations in shade or pattern intensification, possibly related to diurnal/nocturnal cycles or physiological responses, rather than a true active color change mechanism driven by specialized pigment-containing cells?

Answer

Some geckos can change color, but not in the same way or to the same extent as chameleons. Chameleons possess specialized pigment-containing cells called iridophores, which they manipulate to alter the reflection of light, creating dramatic and rapid color changes for camouflage, communication, and thermoregulation. Geckos, on the other hand, generally exhibit more subtle color changes related to factors such as temperature, humidity, light levels, and mood, and the mechanisms involved are often different.

While chameleons rely on active pigment manipulation, geckos typically use a combination of mechanisms:

• Physiological Color Change: This involves redistribution or aggregation of pigment granules within chromatophores (pigment-containing cells). For instance, darker colors may be displayed at night or when cold to absorb more heat, while lighter colors may appear during the day or when warm to reflect sunlight. This process is relatively slow.

• Metabolic Color Change: Changes in metabolism can influence coloration. For example, stress or excitement may cause color changes due to hormonal or other physiological shifts.

• Hydration: The degree of hydration can affect the appearance of some geckos, particularly those with translucent skin. Hydrated geckos often appear more vibrant.

• Reflection of Light: Some geckos have skin structures that diffract light, producing iridescent or shimmering effects, although this is not the same as the active color change seen in chameleons.

Examples of Geckos that Exhibit Color Change:

• Crested Geckos (Correlophus ciliatus): These geckos are known for their color morphs and can exhibit changes in darkness or lightness of their base color, often referred to as "firing up" (becoming darker and more vibrant) or "firing down" (becoming paler). This is largely related to environmental conditions and mood.

• Gargoyle Geckos (Rhacodactylus auriculatus): Similar to crested geckos, gargoyle geckos can also "fire up" or "fire down," displaying more intense colors when active or stressed.

• Panther Geckos (Paroedura picta): They exhibit noticeable color changes between night and day, becoming darker at night.

• Dwarf Geckos (Sphaerodactylus species): Certain species demonstrate slight color changes related to thermoregulation.

In summary, while some geckos can change color, the extent and mechanisms are less complex and dramatic than those seen in chameleons. Gecko color change is usually more subtle and influenced by environmental factors or physiological state, rather than active camouflage or communication.