Axolotl

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Axolotl Care

Ambystoma mexicanum

Axolotls are salamanders endemic to the lake complex of Xochimilco outside of Mexico City. They are best recognized by their retained external gills and tadpole-like body — unlike other salamanders, they do not undergo natural metamorphosis. In captivity they typically live 10–15 years and average 9–10 inches in length, with females growing larger than males.

Sexual maturity occurs at 10 months for males and 12–18 months for females. To determine sex, view the animal from the side — males have a cloacal bulge behind their back legs and females do not. Males may also have black nails, though this trait can be less reliable in some color morphs.

Many color morphs exist in the pet trade, including wild type (mottled black/brown), albino, and leucistic. Though common in captivity and research settings, axolotls are critically endangered in the wild due to pollution and invasive species.

Aquarium Setup

A proper aquarium setup is critical to your axolotl’s health. Recommended minimum sizes are:

  • Juveniles: 10-gallon tank
  • Adults: 20+ gallons

A longer tank is preferred over a deeper one — it gives more room to explore and a higher water volume, which makes maintaining water quality easier.

Axolotls have very delicate skin and gills, so avoid any structures with sharp edges. A good test: run your finger along any silk plant or decoration — if it scratches you, don’t use it. Provide structures where the axolotl can hide and rest to reduce stress and encourage natural behavior.

Live plants can be used but may carry parasites or disease. Strict quarantine and biosecurity measures should be taken before introducing any live plants or a new axolotl to an established tank.

Substrate: Use aquarium sand or large smooth stones (larger than the axolotl’s head). Avoid gravel or small pebbles — axolotls may swallow them and become impacted.

Lighting: Axolotls do not require specific lighting. Soft display lighting works well. As bottom dwellers adapted to low light, they have poor vision but strong olfactory senses. Live plants may require additional lighting.

Filtration

The aquarium must be fully cycled before adding your axolotl and equipped with a filter sized appropriately for the tank. As a general rule, the filter should turn over four times the tank volume per hour (e.g., 20 gallons per hour for a 5-gallon tank). An external canister filter attached to a spray bar inside the tank is recommended to maintain slow, even water flow.

Water Quality & Changes

For a stable aquarium, test water quality at least once weekly and change 10–25% of the water volume weekly. If using tap water, always use a dechlorinator that removes both chlorine and chloramine. The preferred testing kit is the API Freshwater Master Kit.

Key water parameters to monitor:

  • Ammonia: 0 ppm
  • Nitrite: 0 ppm
  • Nitrate: less than 5–10 ppm
  • pH: ideally 7.4–7.6 (acceptable range 6.5–8.0)

Consistency is key with pH. If your axolotl has grown up slightly outside the ideal range and is healthy, do not use pH adjustment products — rapid pH swings can be very harmful. Avoid pH up/down products unless directed by a veterinarian.

Temperature

Water temperature should be maintained between 60–65°F. This requires an aquarium chiller sized appropriately for your tank. An external chiller is recommended to prevent temperature pocketing and maintain consistent water temperature throughout.

Diet & Feeding

Axolotls are carnivores. In the wild they eat mollusks, worms, insect larvae, crustaceans, and occasionally small fish. In captivity, diet by life stage:

  • Larvae (under 1 inch): brine shrimp
  • Juveniles (around 1 inch+): transition to California blackworms
  • Adults: a quality pellet diet such as Rangen Salmon Pellets (soft moist sinking, 3/16″) as the primary food source

Bloodworms, blackworms, tubifex worms, and pieces of earthworm can be offered alongside pellets to vary the diet and provide enrichment. Freeze-dried products provide little nutritional value and are not recommended. Live foods should only be used if sourced from a reliable, parasite- and pathogen-free supplier.

Feed adults 2–3 times per week and remove any uneaten food promptly to preserve water quality. Axolotls are prone to obesity due to their slow metabolism — avoid overfeeding.

Wellness & Preventive Care

Annual wellness examinations are recommended. Schedule a sick visit if you observe any of the following:

  • Lethargy or loss of appetite
  • Skin discoloration, patches, or lumps
  • Gill abnormalities — pale, swollen, or frayed gills
  • Swollen or distended belly
  • Buoyancy issues — floating, sinking, tilting, or erratic swimming
  • Cloudy or protruding eyes
  • Any other concerns

Common Problems

Poor water quality and inadequate husbandry are the most common causes of illness, including inappetence, buoyancy issues, bacterial and fungal infections, and eye and gill disease. Housing axolotls with fish or other axolotls can lead to trauma. Males should not be housed together unless there are enough hides for each individual.

If you suspect your axolotl is sick, please contact us before attempting any treatment. Most over-the-counter remedies do more harm than good, and some medications can damage the beneficial microbiota in your filter that keeps the entire aquarium healthy. Your axolotl’s tank is a living ecosystem — treating your pet means considering the health of the whole environment.