Axolotl Morph Guide

Two Gene Variations

Wild Type

The term "wild type" is used to refer to the most common characteristic of a species under natural conditions, without displaying any defining genetic mutations. Wild type axolotls are typically brownish/greyish and can sometimes have a slightly greenish tint. Wild type axolotls will always have a gold eye ring surrounding a black pupil. They contain melanophores, xanthophores, and iridophores.

Note: The most surefire way to distinguish wild types from copper axolotls is the fact that all copper axolotls will have a red pupil when light is shined on it, while wild type pupils will stay black.

2

Leucistic (White)

Leucism is a genetic mutation which causes white, pale, or patchy coloration in skin, hair, and nails but not the eyes. In axolotls this is caused by a damaged or missing version of Edn3, a gene that codes the protein Endothelin-3 that tells the chromatophores to migrate from the neural crest and spread across the body as an embryo. 

 

Leucism in axolotls presents as a white/pinkish body that still has pigmented eyes with xanthophores and melanophores. A "clean leucistic" will have no melanin on its body other than its eyes while "dirty leucistic" will have scattered melanin on their face and back. A leucistic axolotl with more melanin on the gill stalks than normal are known as "dark gill leucistics".

3

Albino (Golden Albino)

Albinism is a genetic mutation that results in a partial or complete absence in skin pigment. Albinism in axolotls results in the loss of melanophores. However, xanthophores are still present, resulting in their yellow coloration. Albino axolotls can also have iridophores.

4

Melanoid

Melanoid axolotls completely lack iridophores and some xanthophores. This results in increased melanophores (dark coloration) on the whole body, as opposed to only scattered spots in wild types and other morphs. This causes melanoid axolotls to have very few spots.

 

Note: Melanoid and Axanthic are the only two morphs that can never have iridophores or eye rings.

5

Copper

Copper is a form of albinism, resulting in partial loss of pigment. Copper axolotls lack the enzyme, Tyrosinase, that normally oxidizes pheomelanin (responsible for red pigmentation) into eumelanin (responsible for dark coloration). Without this enzyme, they are unable to "convert" red pigmentation into darker pigmentation. This results in their spots of orange pigmentation, rather than the dark brown spots of a wild type. It also results in their inability to produce fully black pupils, thus resulting in their characteristic red reflective ones. Copper axolotls may have iridophores.

Note: The most surefire way to distinguish wild types from copper axolotls is the fact that all copper axolotls will have a red pupil when light is shined on it, while wild type pupils will stay black.

4

Axanthic

Axanthicism is a genetic mutation that causes animals to be unable or only partially able to produce xanthophores (yellow pigments). In axolotls, axanthicism results in a complete loss of xanthophores and iridophores. This results in their characteristic greyish color, along with spots of melanophores (dark pigments) all over the body. Axanthics are also unable to have an eye ring.

Note: Melanoid and Axanthic are the only two morphs that never have iridophores or eye rings.

4

Axanthic

Axanthicism is a genetic mutation that causes animals to be unable or only partially able to produce xanthophores (yellow pigments). In axolotls, axanthicism results in a complete loss of xanthophores and iridophores. This results in their characteristic greyish color, along with spots of melanophores (dark pigments) all over the body. Axanthics are also unable to have an eye ring.

Note: Melanoid and Axanthic are the only two morphs that never have iridophores or eye rings.

4

Axanthic

Axanthicism is a genetic mutation that causes animals to be unable or only partially able to produce xanthophores (yellow pigments). In axolotls, axanthicism results in a complete loss of xanthophores and iridophores. This results in their characteristic greyish color, along with spots of melanophores (dark pigments) all over the body. Axanthics are also unable to have an eye ring.

Note: Melanoid and Axanthic are the only two morphs that never have iridophores or eye rings.

4

Axanthic

Axanthicism is a genetic mutation that causes animals to be unable or only partially able to produce xanthophores (yellow pigments). In axolotls, axanthicism results in a complete loss of xanthophores and iridophores. This results in their characteristic greyish color, along with spots of melanophores (dark pigments) all over the body. Axanthics are also unable to have an eye ring.

Note: Melanoid and Axanthic are the only two morphs that never have iridophores or eye rings.

Glossary

Melanophore - Cell that contains melanin

Xanthophores - Responsible for yellow pigmentation

Iridophore - Pigments that reflect light

Melanin - Brown/black pigment

Eumelanin - The most common form of melanin; brown/black pigment

Pheomelanin - Responsible for red, yellow, and pink hues

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Reference

Strohl, L. Axolotl - Genetics - General Audience. https://docs.google.com/document/d/1kjdtH5JjnsXTe-IvbrT4kRnwCQTeHXTwmcSyUZtV4d4/edit

Strohl, L. Axolotl - Genetic Variations of Axolotls. https://docs.google.com/document   /d/114QWTco6AVoQd_66kuGrRn1NtGl-EckrHQTRZ6v_9bw/edit#heading=h.vsuaxzlcggi