Axolotl
A salamander that never leaves the water or loses its gills, and it regrows a lost limb. The wild population survives in one lake system in Mexico City.
Overview
The axolotl never grows up, and that is the whole animal. It is a paedomorphic salamander, which means it keeps its larval body into adulthood and breeds in it: feathery external gills, a finned tail, and a life spent entirely in water rather than on land. Most salamanders lose all of that at metamorphosis. This one almost never does.
It comes from two high altitude lakes near Mexico City, Chalco and Xochimilco, at around 2,274 m, and the IUCN lists it as Critically Endangered in the wild. The animals in the hobby are captive bred and have been for generations.
Temperament
Placid, slow and entirely aquatic. An axolotl spends most of the day on the bottom and moves when there is food. It has no interest in being handled, and the skin is delicate enough that handling is best kept to moving one between containers.
They are predators, and they are cannibals. ADW records conspecifics in the wild diet, and juveniles kept together will take each other's gills and limbs. Regeneration is real and the limbs generally come back, but a tank of young axolotls is a tank where something is always regrowing.
Care and grooming
Earthworms are the staple, with sinking pellets as an alternative. Adults eat every two or three days rather than daily.
Temperature is the one thing that decides whether an axolotl thrives. They come from cold high altitude water, they want 60 to 64 F, and above about 72 F they stop eating and become vulnerable to infection. In most houses that means a chiller or a cool room rather than a heater, which is the opposite of nearly everything else on this shelf.
Living and exercise
Twenty gallons long, fully aquatic, filtered gently because they dislike current. Gravel is the classic mistake: an axolotl feeds by suction and swallows what is near the food, and gravel small enough to swallow causes impaction. Bare bottom or sand large enough not to be inhaled is the safe answer.
No UVB, and low light. Bright lighting stresses them, so a planted tank with floating cover and a shaded hide suits them better than a display lit for plants.
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