Geckos are small lizards known for their ability to cling to smooth surfaces. They have specialized toe pads that allow them to adhere using van der Waals forces. While geckos are typically brown, grey, or green in color to camouflage with their environments, through selective breeding and genetic mutations, captive geckos can display a variety of bright colors like purple. So what makes a purple gecko purple? The answer lies in pigments, genetics, and light reflection.
Pigments
The predominant pigments that contribute to gecko skin and eye coloration are melanins and carotenoids. Melanins come in two forms: the dark brown eumelanins and the lighter red and yellow pheomelanins. Carotenoids are yellow, orange, and red pigments. Various combinations and concentrations of these pigments along with structural colors can create the purple hue.
Violet and purple hues are created through a high concentration of melanins and low levels of carotenoids and pteridines. The exact blend of eumelanin, pheomelanin, and lack of other pigments absorbs all wavelengths of light except those in the violet-purple spectrum, which are reflected back to our eyes. The more melanin, the darker the purple color.
Genetics
Selective breeding has allowed breeders to develop vibrant purple color morphs in various gecko species. The genes responsible for purple or lavender coloration are recessive. This means geckos must inherit a copy of the mutant gene from both parents to display the purple phenotype.
Some common purple or lavender color mutations include lavender tremper albino leopard geckos, purple passion crested geckos, and African fat-tailed geckos with purple hypomelanistic genetics. Each mutation arose spontaneously but can now be consistently reproduced when two proper parent geckos are bred together.
Structural Coloration
In addition to pigment concentration, the physical structure of the skin also affects color. Iridophores are reflective cells containing plates and crystals that interfere with light. Depending on the spacing and orientation of these particles, different wavelengths are reflected, enhancing or modulating color.
Light scattering from iridophores combined with purplish-red skin pigmentation helps create the brilliant violet shades seen in purple geckos. Iridophores develop as the gecko matures, which is why juvenile geckos often appear slightly different colored than adults of the same morph.
Diet
Carotenoid pigments are obtained through the diet and are responsible for yellow, orange, and red hues. A gecko’s diet can have a subtle influence on color, though melanin content is the primary driver of purple coloration. Providing carotenoid-rich feeder insects may help maintain vivid coloration.
| Feeder Insect | Carotenoid Content |
|---|---|
| Mealworms | Moderate |
| Waxworms | Low |
| Crickets | High |
| Roaches | High |
Color Change
Geckos can dynamically change color to a limited degree through redistribution of pigment granules in special cells called melanophores. This allows them to darken or lighten their skin slightly. While they can’t turn purple at will, this mechanism does allow them to become somewhat lighter or darker purple based on mood, temperature, and light environment.
Bright and Vibrant
Selective breeding has brought out the best of gecko genetics to produce beautiful vibrant colors beyond what occurs naturally in the wild. Purple is a rarely occurring color in nature, but thanks to creative and meticulous breeding programs, we can now admire the regal beauty of purple geckos. From genetics to pigments and structural facets, many biological factors all culminate in the creation of these exotic and captivating colors.
Causes of Color Change
A number of factors can cause color change or loss in purple geckos:
Shedding
Geckos shed their skin in one piece in a process called ecdysis. Before shedding, the old dull skin layer obscures the new vivid skin underneath. This causes the gecko to appear faded and patchy. After a successful shed, purple coloration returns to normal.
Temperature
Low temperatures can cause a gecko to darken and appear more drab. Maintaining an adequate basking spot and ambient temperature in the tank helps keep hues vibrant. Ideal temperature range is 85-90 F on the warm end.
Lighting
Exposure to UVB lighting is important for the expression of bright gecko colors. Without proper lighting, purple hues may fade or develop a washed out appearance.
Stress
Stress can disrupt normal pigment production and cause temporary color change. Once the source of stress is removed, normal bright color will return with the next shed.
Injury
Skin injuries, abrasions, or loss of the tail tip can lead to scar tissue formation and abnormal pigmentation in the affected area. This results in permanent localized discoloration.
Illness
Certain illnesses may impact color expression. If a systemic infection or disease disrupts normal metabolism, pigment synthesis decreases leading to duller colors. With treatment and resolution of the medical issue, previous coloration will be restored.
Old Age
Older geckos may start to exhibit faded or dulled skin pigmentation as metabolism slows down. This effect is most noticeable in very senior animals near the end of life. Supplementing with carotenoids could potentially help maintain vibrance.
Conclusion
Attaining a brilliant purple color requires the right combination of pigments, genetics, and cellular structures. Captive breeding allows us to produce colors rarely seen in the wild. Responsible care and housing helps maintain these exotic hues throughout a gecko’s life. With proper husbandry, you can enjoy the vibrant beauty of your purple gecko for years to come.
