Nick Upton / Axolotl / Mexican salamander (Ambystoma mexicanum), golden albino form, critically endangered in the wild, UK captive.

Claudio Contreras / Axolotl (Ambystoma mexicanum), captive. Critically endangered species.

Alejandro Prieto / Axolotl (Ambystoma mexicanum) swimming in a shallow stream, Manantlan reserve, Jalisco, Mexico. Critically endangered.

Alejandro Prieto / Axolotl (Ambystoma mexicanum) floating dead on surface of polluted river surrounded by litter. Axolotls are very sensitive to water contamination, they are indicators of water quality. The main threat...

Alejandro Prieto / Two Dominican nuns weighing an Axolotl (Ambystoma mexicanum). The nuns are part of the only religious organization that actively participates in conservation projects in Mexico, they help to encourage...

Alejandro Prieto / Close up of Axolotl (Ambystoma mexicanum) head and gills on white background, Mexico.

Alejandro Prieto / Glass slide showing the skeleton of an Axolotl's (Ambystoma mexicanum) hand, CINVESTAV research center, Irapuato, Mexico.

Alejandro Prieto / Axolotls (Ambystoma mexicanum), a popular pet around the world, for sale illegally, inside the black market of animals "Mercado Mixhuca" alongside other illegal species, Mexico City, Mexico.

Alejandro Prieto / Axolotls (Ambystoma mexicanum), a popular pet around the world, for sale illegally, inside the black market of animals "Mercado Mixhuca" alongside other illegal species, Mexico City, Mexico.

Alejandro Prieto / Axolotl (Ambystoma mexicanum) resting underwater next to its eggs, Sierra de Manantlan, Mexico.

Alejandro Prieto / Axototl (Ambystoma mexicanum) portrait, on white background, Mexico.

Alejandro Prieto / Axototl (Ambystoma mexicanum) swimming in pond, Mexico.

Alejandro Prieto / Axolotl (Ambystoma mexicanum) swimming in a small pool surrounded by trees, Sierra de Manantlan, Mexico.

Alejandro Prieto / Axolotl (Ambystoma mexicanum) underwater surrounded by lush aquatic vegetation, Mexico.

Alejandro Prieto / A young Axolotl ( (Ambystoma mexicanum) without limbs, with the leg of an adult in the foreground, on white background, Mexico.

Alejandro Prieto / Microscope image of a newborn Axolotl (Ambystoma mexicanum) showing external gills, tail and two projections on both sides of the head, Mexico.

Alejandro Prieto / Gills of a juvenile Axolotl (Ambystoma mexicanum) seen through the microscope, CINVESTAV research center, Irapuato, Mexico.

Alejandro Prieto / Silhouette of Axolotl (Ambystoma mexicanum) swimming in a woodland stream surrounded by towering trees, Sierra de Manantlan, Mexico.

Alejandro Prieto / Two Axolotls ((Ambystoma mexicanum) on white background, portrait, Mexico.

Alejandro Prieto / Axolotls (Ambystoma mexicanum) in containers of water after being caught from the wild by scientists studying them, Sierra de Manantlan, Mexico.

Alejandro Prieto / Axolotl (Ambystoma mexicanum) caught by scientists in trap made of fine cloth, Sierra de Manantlan, Mexico.

John Cancalosi / Axolotl (Ambystoma mexicanum) captive, occurs in Mexico. Critically endangered, endemic species.

John Cancalosi / Axolotl (Ambystoma mexicanum), white or leucistic form, neotenic salamander. Captive, critically endangered in the wild, occurs in Mexico.

John Cancalosi / Axolotl (Ambystoma mexicanum), white or leucistic form, neotenic salamander. Captive, critically endangered in the wild, occurs in Mexico.

John Cancalosi / Axolotl (Ambystoma mexicanum), white or leucistic form, neotenic salamander. Captive, critically endangered in the wild, occurs in Mexico.

Sylvain Cordier / Axolotl (Ambystoma mexicanum) portrait, captive, endemic to Mexico.