Geckos are a diverse group of small lizards found in tropical and temperate regions around the world. While most geckos have coloration that helps them blend into their environments, some species are white or nearly white in appearance. The white coloration is rare in the reptile world and quite striking when seen on a gecko. But what causes these geckos to be white, and what species of geckos exhibit this unique coloration?
In this article, we will examine some of the different types of white geckos and discuss their natural history and origins. Understanding what makes them white can provide insight into genetics, evolution, and adaptation in these fascinating reptiles. We will also look at how their bright coloration may play a role in mating and signaling. By the end, you should have a better appreciation for these uniquely pale lizards.
Genetics Behind White Coloration
So what exactly causes the white coloration seen in some geckos? The genetics behind this trait have been studied in a few different white gecko species.
In many cases, the white appearance is caused by the total lack of black pigment cells called melanocytes in the skin. This results in an animal that appears pink or white when viewed against the white background color of the bones and tissues underneath the skin. This condition is known as leucism. Leucism is caused by genetic mutations that inhibit the migration or development of melanocytes during embryonic development.
Another possible genetic cause of white coloration is a condition called albinism. Albinism is the total lack of melanin pigment production. This results from mutations in genes involved in melanin synthesis pathways. Without melanin pigment, animals appear white or pale yellow. Albinism is rare in wild populations as the lack of pigment leaves animals at greater risk from sun exposure and predation. But albino individuals are sometimes seen in captive bred populations.
Some white gecko species may actually still produce small amounts of melanin, just greatly reduced from normal levels. These hypomelanistic or pigment-reduced forms are caused by genes that lower but don’t completely eliminate melanin synthesis. This can result in geckos that are dull white or grayish in appearance.
Examples of White Gecko Species
Now let’s look at some specific examples of white geckos and what genetics may underlie their unusual coloration.
White-Lined Gecko
One of the most striking white geckos is the white-lined gecko, also known as the Singapore white-lined gecko or penny gecko. Native to Southeast Asia, these small geckos have black skin accentuated by thick white bands and spots. Their scientific name is Gekko vittatus.
It is thought that the white patterning in Gekko vittatus is caused by leucism. The white bands lack melanin cells while the black regions contain normal melanin. The high contrast makes their coloration very conspicuous. Some individuals may also show signs of hypomelanism or reduced melanin rather than a complete absence.
| Scientific Name | Gekko vittatus |
|---|---|
| Common Names | White-lined gecko, Singapore white-lined gecko, penny gecko |
| Native Range | Southeast Asia |
| Length | Around 5 inches |
| Coloration | Black with thick white bands and spots |
| Genetics | Leucism |
Leopard Gecko
The leopard gecko, Eublepharis macularius, is a crepuscular ground-dwelling lizard from the deserts of Asia. They are popular pet reptiles. Selective breeding has produced a variety of color morphs including white.
White coloration in leopard geckos can be caused by either leucism or albinism since both conditions occur. Leucistic specimens will retain black eyes and faint banding while albino leopard geckos have pink eyes and pale yellow coloration. These albino morphs are sometimes called “blazing blizzards” or “snow geckos” in the pet trade.
| Scientific Name | Eublepharis macularius |
|---|---|
| Common Names | Leopard gecko |
| Native Range | Afghanistan to northwestern India |
| Length | 8-10 inches |
| Coloration | Yellowish, pale pink or orange. Albinos have pink eyes. |
| Genetics | Leucism or albinism |
Crocodile Gecko
The crocodile gecko (Lepidodactylus lugubris) is a tropical gecko native to islands in the Pacific and Indian Oceans. It gets its name from the rough, warty skin reminiscent of a crocodile. The body is covered in irregular black spots and patterns over a light brownish background. But all white individuals called “lugubris albinos” also occur.
These white crocodile geckos are true albinos, showing a complete lack of black and brown pigment. The eyes are pink and the body is creamy white and yellow. Albino crocodile geckos are rarely found in the wild but are bred in captivity. They may have reduced survival in the wild due to greater visibility to predators.
| Scientific Name | Lepidodactylus lugubris |
|---|---|
| Common Names | Crocodile gecko |
| Native Range | Pacific and Indian Ocean islands |
| Length | 5-8 inches |
| Coloration | White or yellowish, pink eyes |
| Genetics | Albinism |
Purpose of White Coloration
The rarity of white coloration in wild gecko populations implies there may be some disadvantages. Loss of camouflaging pigmentation likely increases visibility to predators. Melanin also protects against UV damage which could impact survival. Yet the unique coloration has been maintained in some populations. This suggests there could be some benefits as well.
One possibility is that the bright white coloration makes the geckos more visible in low light conditions. Many geckos are most active at dawn and dusk so increased visibility in low light may help with activities like hunting for prey or communicating with other geckos.
The banding patterns seen in white-lined geckos may also serve as disruptive camouflage when viewed against mottled backgrounds. And even purely white geckos like albino leopard geckos may still blend into white or lightly colored rock surfaces in their native habitats during the day when inactive.
Another potential advantage of leucism or albinism is that it makes geckos appear distinctly different than normal individuals. Unusual coloration is sometimes used as an indicator of fitness or breeding quality in mate selection. When given a choice, female geckos may preferentially select more brightly colored or albino males. The rare coloration signifies overall genetic vigor. So white coloration could provide an advantage in reproductive success and passing on genes to future generations.
Care of White Gecko Morphs
The unique appearance and genetics of white geckos means they require some specialized care, especially when kept in captivity. Here are a few key considerations:
– Provide ample shelter and hiding spots – Lack of pigment means albino and leucistic geckos are easier for predators to see. Proper housing should include plenty of hides, plants, and other decor to allow them to feel secure.
– Monitor time in sunlight – While some UV exposure is important for vitamin D3 synthesis, limit direct sun exposure which could lead to sunburn and skin damage.
– Supplement with calcium and vitamins – Albino geckos may be prone to metabolic bone disease. Proper supplements are key along with UVB lighting.
– Breed carefully – Breeding two albino geckos together could result in offspring with even poorer health and survival. Outcrossing with normally pigmented geckos is recommended.
With attentive care, these remarkable white lizards can thrive in captivity and showcase their unique genetics and beauty. Responsible breeding programs help maintain rare albino and leucistic color morphs.
Conclusion
While most geckos rely on cryptic coloration for camouflage and sun protection, unusual genetics produce some strikingly white species. Leucism, hypomelanism, and albinism can all manifest as white coloration through various mutations affecting pigment synthesis and migration during development. Examples like the white-lined gecko, albino leopard geckos, and crocodile geckos demonstrate the diversity of geckos exhibiting these rare traits.
There are likely some costs to lacking normal pigmentation. But behaviors like seeking sheltered microhabitats may compensate and provide other advantages like visual signaling. Their peculiar coloration makes white geckos fascinating to study and observe in both wild and captive populations. With specialized care, reptile enthusiasts can successfully maintain these beautiful albino and leucistic morphs.
