Black Night Leopard Geckos
A top Black Night is solid black with no visible pattern, the result of generations of breeding for darkness. Quality runs from dark with pattern to total black, so judge the animal in front of you, kept at normal temperatures, rather than the name.
About the Black Night gene
The Black Night is a line of leopard geckos that are hypermelanistic. Breeders have worked on this line for many generations to produce darkness until the best animals are black from nose to tail. This is the best known of the dark lines. Because keepers buy one for the colour, the grade of the individual animal matters more than the name on the label.
Appearance
A top-grade Black Night has no visible pattern and is solid black across the tail and back. Most are not. The line runs from total black, through black animals with a clearly visible pattern, to very dark geckos whose markings still show through. From pairings into lighter stock, animals can come out only a shade darker than a normal. As they grow, hatchlings can show pattern that the black swallows. Temperature affects the depth of colour. A gecko raised cool can look darker than it will stay once it is kept at normal temperatures. Ask for current photos of the animal as it is kept now.
Genetics
Because Black Night is polygenic, it is not carried by a single gene. This means there is no super form and no het. The names Black Night and Pos Black Night are used in listings. How dark the young come out depends on how dark the parents are. Breeding a gecko from outside the line results in lighter offspring, and it takes generations of breeding back into dark animals to regain the black. Some breeders combine other lines and Mendelian genes with the line. You can find combinations like Black Night tangerines and Mack Snow Black Nights on the market. Rather than being other names for Black Night, Carbon, Charcoal and Black Pearl are separate dark lines. In the Netherlands, Ferry Zuurmond and Roy Sluiter began work on the line around 1997.
Known issues
The pure line has lost some vigour due to long line breeding. Breeding pure Black Nights often results in smaller, slow growing animals. Those breeders working them report poor fertility, including bad eggs, fertile eggs that die before hatching, and some hatchlings with kinked tails. To counter it, breeders outcross to unrelated stock and then breed the darkness back.