Axolotl

Overview

Axolotls are salamanders that spend their whole lives in water. They keep the feathery external gills and finned tail of a larva into adulthood ²³. Most adults reach 9 to 10 inches (23–25 cm), though some reportedly reach 12 to 15 inches. Females are larger ²³. They usually live 10 to 15 years, and some reach 20 ²³.

Axolotls can regrow lost limbs and parts of the tail, heart and nervous system, which is why scientists have studied them for years ²³. Wild-type axolotls are black to mottled brown. Captive breeding has produced melanistic, leucistic and albino forms, and lab work has produced a "GFP" line that glows green under UV light ².

Natural history

Wild axolotls live only in Lake Xochimilco, its canals and a few nearby waterways of Mexico City. Lake Chalco was also part of their historic range ²³. Shrinking habitat as Mexico City grew, along with collection for the pet trade and for food, has left them critically endangered in the wild ²³. Fortunately, most pet axolotls are captive-bred stock ²³. They're close relatives of the tiger salamander but rarely transform into a land-dwelling adult ².

Enclosure

• Tank size. Tree of Life recommends at least a 20-gallon long tank for one axolotl, plus at least 10 gallons for each additional one ¹. LafeberVet suggests 10 gallons for juveniles and 20+ for adults, and notes that bigger tanks keep water quality stable longer ². Floor space matters more than height ¹.
• Gentle filtration. Use a sponge or canister filter with low flow, or a spray bar to break up the current. Strong flow stresses them and damages their gills ¹²³.
• Cycle first. Cycle the aquarium before your axolotl moves in ¹.
• Hides. Plants, rocks or décor too big to swallow ³.
• Tankmates. Keep axolotls only with similar-sized axolotls. Fish nip gills or get eaten, and juveniles are cannibalistic ¹². Males shouldn't share a tank without plenty of hiding space ².
• Light. Keep it dim, because bright light stresses them ².

Temperature & lighting

Axolotls are cool-water animals, and overheating is a common cause of illness ¹.

Keep the tank in a cool room away from windows and heaters, and use a fan or aquarium chiller in hot weather ¹.

Humidity

Not applicable for this fully aquatic animal. Water quality is everything ¹²:

• Ammonia and nitrite: 0 ppm
• Nitrate: below 40 ppm (Tree of Life) or ideally below 10 ppm (LafeberVet); prolonged high nitrate can cause eye problems
• pH: 6.5–8.0, with 7.4–7.6 preferred
• Water changes: 20–30% weekly with dechlorinated water, checked with a liquid test kit

Substrate

Use a bare bottom or fine sand ¹². Axolotls feed by suction and swallow what they suck in, so never use gravel or small pebbles. They cause blockages that can be fatal ¹²³. If you want stones, use large river rocks ².

Diet & supplementation

• Foods. Sinking axolotl or carnivore pellets and earthworms or nightcrawlers, with bloodworms, blackworms and brine shrimp for variety ¹².
• Earthworms. LafeberVet suggests cutting earthworms into pieces, after reports of stomach perforation in tiger salamanders fed whole live nightcrawlers ².
• Schedule. Feed juveniles daily and adults every 2–3 days ¹²³.
• Portions. VCA suggests only what they finish in 2–5 minutes, and Chicago Exotics 5–10 minutes. Remove leftovers ³⁴.
• Obesity. It's common and shortens their lives ²³.

Handling & temperament

Don't handle axolotls unless it's medically necessary. Their skin is delicate and porous and their gills are fragile, and rough handling can even cost a limb ¹³⁴. Move them with a soft net or a container. If you must touch one, wear clean, powder-free nitrile gloves ¹²⁴.

Health

Common issues (most trace back to husbandry ²)

• Heat stress. Floating, poor appetite, swelling ¹²³.
• Ammonia or nitrite poisoning. Excess nitrite can make their eyes bulge ¹³.
• Fungal infections. White, cottony tufts on gills or skin need prompt vet care ¹².
• Bacterial infections, often from Aeromonas or Pseudomonas ².
• Gravel impaction ²³.
• Obesity ²³.
• Gill damage from strong water flow ³.

LafeberVet notes that some common fish medicines, including tetracyclines, malachite green and copper-based treatments, are unsafe for axolotls. Don't medicate without a vet ².

When to see a vet

Get help for cottony growths, red or damaged skin or gills, floating, a swollen body, refusing food, or any injury, which can still get infected even though they regenerate ¹³.

Breeding overview

Males mature at around 10 months and females at 12 to 18 months, at roughly 18 cm (7 in) long ². Mature males have a swollen vent and dark nails ². Keep juveniles sorted by size, because they eat each other ².

Legal & ethics

• CITES. Ambystoma mexicanum is listed in Appendix II, so international trade requires permits ⁵.
• U.S. federal law. In January 2025 the U.S. Fish and Wildlife Service added the genus Ambystoma, which includes axolotls, to its injurious wildlife list to keep out salamander chytrid fungus (Bsal) ⁶⁷. Importing them, or shipping them between the continental U.S., Hawaii, Puerto Rico, D.C. and U.S. territories, now needs a permit. However, moving them between states within the continental U.S. isn't federally prohibited ⁶.
• If you already own one. You don't need to do anything, as long as the animal has never been covered by a permit ⁶.
• Never release one. Find a legal, responsible new home if you can't keep it ⁶.
• Local rules. States can have their own rules, so check locally.

Sources

1. Axolotl Care · Tree of Life Exotic Pet Medical Center
2. Basic Information Sheet: Axolotl · LafeberVet
3. Axolotls as Pets · VCA Animal Hospitals
4. Axolotl Care · Chicago Exotics Animal Hospital
5. CITES listing: Ambystoma mexicanum · Species+ (UNEP-WCMC and CITES Secretariat)
6. Salamanders as Injurious Wildlife: What It Means for Owners and Scientists (FAQs) · U.S. Fish and Wildlife Service
7. Injurious Wildlife Species; Listing Salamanders Due to Risk of Salamander Chytrid Fungus (90 FR 2170) · Federal Register (U.S. Fish and Wildlife Service)

Last reviewed 2026-10-24 by Novel Fauna. This guide is general husbandry information, not veterinary advice. When an animal is sick, see a veterinarian experienced with exotic animals.

Revision history

1. 2026-10-24 Library: fix source frontmatter, hognose difficulty, fallback guide links, hero copy a22966a
2. 2026-10-24 Library: 50 cited care guides, /library/[slug] route, coming-soon cards, SLUGS.txt synced to species.guide_slug 228ce54

Evidence grades: Novel Fauna editorial: source classification, not yet expert-reviewed, 2026-10-25. What the grades mean.

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