DEVELOPMENTAL BIOLOGY A wild-type leopard gecko hatchling. Image credit: Adrien Debry, Florent Montange, and Athanasia Tzika (University of Geneva, Geneva, Switzerland). How leopard geckos get their spots The yellow and black bands on the skin of leopard gecko hatchlings morph into black spots as the geckos mature into adults. Asier Ullate-Agote and Athanasia Tzika used high-resolution microscopy to analyze the change in leopard gecko skin.