Axolotl Colour Guide.

Axolotls and their colours.

What are axolotls?

An axolotl (Ambystoma Mexicanum) is a type of salamander which originated from Mexico, originally native to Lake Xochimilco and Chalco. Unfortunately due to the expansion of nearby cities, many attempts to re-establish axolotls in the area have failed and axolotls are now on the CITES endangered species list. However, captive populations are booming due to the pet trade and the importance of axolotls in scientific research due to their regenerative abilities.

Many people enjoy keeping axolotls as pets due to their unique look, their ability to regrow lost limbs, they stay fully aquatic (although they do have a tiny pair of lungs) and because they do not undergo metamorphosis in their life, unlike other amphibians. Axolotls are neotenic, meaning they stay in their 'larval' stage, reaching sexual maturity in the larval stage and growing larger than other larval salamanders. There is the rare occasion where an axolotl will spontaneously morph, meaning that it loses it's gills, changes body shape, so that it is able to live on land.

Colours

Wildtype

The wildtype axolotl is a combination of brown, green and black, some may have speckles of shiny gold iridophores. It is called the wildtype as it is the natural colour of axolotls - if you saw one in the wild, this is what you would see. They may darken with age, with some appearing black, although the light and dark variations still occur. Some can be extremely light and very green, others can take a more muddy appearance. They have shiny rings in their eyes, which is how you are able to tell them apart from melanoids.

Melanoid

A melanoid axolotl will have a large amount of dark pigment, and lack shiny pigments compared to a wildtype. They don't have possible golden specks on their bodies like a wildtype can, and their eyes do not have a shiny ring in them. They look more 'matte' than a wildtype.

Leucistic

Leucistic axolotls are the one's that people commonly recognise, they are the white axolotls with red gills. They have black eyes. They may have a very light dusting of black pigment across their face and back. Some have blue tints to their gills and these are known as 'blue gilled leucistics'.

Dirty leucistics have a larger amount of black pigment across their faces and backs, making them look 'dirty'. Heavily dirty ones are not very common, compared to the 'normal' leucistic.

Albinos

There are several types of albino. The first one I'll address is the golden albino. Because it is an albino, it has to have pale eyes which either appear red or yellow. Due to the albinism, they have no melanophores which makes it look gold with the over expression of xanthophores. Some have iridophores which appear almost like white shiny patches against the yellow skin. The older they become, the paler they may become.

There is another variation of the albino called the melanoid albino, which looks similar to golden albinos, except they have no iridophores. They do not have the shiny pigment or shiny eyes.

Normal albinos look like leucistics except they lack the melanophore pigmentation, so no black eyes and no dusting of pigment. They will have the iridophores, perhaps in the gills and they will have them in their eyes.

Coppers

There are also copper axolotls. How they are created is still unknown, but we do know that they are albino in nature, as they lay white eggs and have red eyes (which can be very hard to see), it is why they do not have any dark spots on them (no melanophores). Instead they have a variety of different shades of brown as their spots and commonly have red gills. They are also known as 'olive' axolotls in Australia.

Axanthic

Axolotls that come with the label 'axanthic' mean they are lacking in any yellow pigment, they don't have any xanthophores or iridophores.

GFP

Axolotls that come with the label 'GFP' are bred from genetically modified axolotls who carry the fluorescent protein. They glow under black lights, and take on green and yellow tinges, with glowing eyes. It is not just light axolotls who can be GFP's, as displayed in the photographs.

Mosaic

Mosaic axolotls are rare. They occur during development, when a cell or cluster of cells randomly mutates. Sometimes this alters the genetic colour, so the normal cells are one colour and the altered ones are a different colour. People falsely believe that it is from the fusing of two eggs. This is incorrect. Chimera axolotls do not exist - they are simply mosaics.