They are not fish. They are amphibians. They have gills as well as lungs but must remain in water or they will dry out. They originate from Mexico and are basically extinct at this point. There are scientists/researchers working to get a population kick started but when the habitat is polluted to the point that it is currently there is little hope.
They are very popular as pets though so they will live on long after they are truly extinct in the wild.
The biggest reason they made it in to the pet trade here in the US is due to the research done on their ability to regenerate lost body parts. I have seen first hand their ability to re-grow a lost limb. In the lab that limb would have been surgically removed, in the wild or in an aquarium the limb may be removed by a tank mate. Although they do not have teeth they are like little alligators when they grab a tank mates leg or tail or food. They latch on and very seldom let go till the limb, or mouthful of whatever is separated from its anchor point.
Tank/Aquarium:
They are best kept in cold (70 F) clean still water with no substrate or sand, no rocks or gravel. They do not have the ability to close their eyes so light is not needed. They do like to hide under or inside of large rocks or ornaments. I like to use terracotta pots or PVC fittings. As far as the size of the tank goes there is no set size requirements. As long as the Axolotl looks comfortable, can turn around, swim around, they should be fine. Keep in mind that longer tanks are better than taller tanks. Always go with a bigger tank if possible since water quality will hold better in a larger volume as well as temperature. For example, 20 gallon longs work well for one or two axolotls. 40 gallon longs work well for 4-5. maybe 6 axolotls. Eggs and hatchlings can be kept very comfortably in dollar store shoe storage container boxes that are long, wide, and shallow. Keep in mind to not crowd the hatchlings.
Food:
Live brine shrimp as hatchlings up till they can eat bloodworms, then as soon as they can start eating pieces of worm that is the main food for them. As they grow larger so can the pieces of worm until they reach a size that whole worms are fine.
I will get more in depth in future blogs.
