Axolotls are a neotenic salamander that will stay aquatic for its entire life span, which is on average, 15 years. They require cold water ideal range being 60°F to 65°F, but should not be colder than 50°F or hotter than 69° for an extended length of time. Gravel and rocks smaller than the palm of your hand should never be placed in their aquarium as this can lead to impaction. Sand (when 5 inches or longer), tile, and bare bottom are all suitable for the bottom of the aquarium. They can eat a variety of carnivorous foods, worms being the most nutritious.