The leucistic axolotl is the white morph. It has little pigment in its skin but keeps dark eyes, which tells it apart from an albino.[1][2]
Appearance
Leucistic axolotls have few or no black pigment cells, and most of their yellow and shiny pigment cells are missing too, so the animal looks white or pale pink.[1][2] The eyes stay dark. Some adults grow patches of dark pigment cells later in life.[1]
Genetics
The morph is caused by a fault in the gene edn3, which makes the signal molecule endothelin 3. It is recessive, so an axolotl is leucistic only if it inherits the fault from both parents.[1][2] Adding a working Edn3 gene to a leucistic animal restores its pigment.[1]
History
A white axolotl was among the animals collected by a French military expedition at Xochimilco in 1863, together with 33 animals of the wild colour.[1] Whether leucistic axolotls still occur in Xochimilco today is not known.[2]
Health
The stock center says that lethal recessives are not expected to appear when white axolotls are bred.[3] No eye or skin problem linked to the morph is reported in the sources used here.[3][2]
Popularity
White axolotls were in Europe early, but it was only at the beginning of the 20th century that they became more widely available.[4] White is one of the four pigment mutants kept by the stock center, and white mutants helped to show that the pigment cells of vertebrates come from the neural crest.[5][1] All colour mutants known to research are also available in the pet trade.[6]
Sources
- Woodcock et al. 2017, Scientific Reports 7: 6 (mutant genes and tiger salamander DNA in laboratory axolotls)
- Kabangu et al. 2023, Genes 14: 904 (the melanoid gene)
- Ambystoma Genetic Stock Center, University of Kentucky, axolotl strains
- Reiss 2022, “Cut and paste: the Mexican axolotl 1864–present”, Frontiers in Cell and Developmental Biology 10: 786533
- Voss & Muzinic 2024, Introduction to the Laboratory Axolotl and Ambystoma Genetic Stock Center
- Tyrp1 and the axolotl copper mutant, Scientific Reports 2024