Axolotls as Pets

In general Axolotls (also known as the Mexican Walking Fish) can be a great low maintenance pet. Axolotls need a proper aquarium, healthy food, good filtration, an air diffuser for plenty of oxygen rich clean water and lighting that simulates their natural environment. These solitary amphibians are not aggressive and have a calm and docile nature. They will interact with their owners and love to hunt for food and explore their surroundings. Axolotls do not enjoy being handled and should not be removed from the tank.

In this article we will cover what you need to know before getting an Axolotl. Topics such as aquarium requirements, diet and water quality. We will also include tips for both beginner and advanced owners.

Getting to Know More About Axolotls

Unlike most amphibians, Axolotls are neotenic. This means they reach sexual maturity at an early age which results in growing into adulthood without losing their juvenile features. For Axolotls this means they will never grow out of their adorable gills and evolve into a land creature.

There is only one species of Axolotl, but they come in a wide variety of colors. The most common are the wild brown and leucistic. The leucistic variety have a loss of pigmentation that develops into colors ranging from pink and white to patchy discolorations across the body of the axolotl.

Some of the most popular colors among pet owners are the albino and melanistic axolotl.

Both the golden and the exotic chimera axolotl are rarer but are growing in popularity and availability.

One of the fastest growing trends in new axolotl colors is Green Fluorescent Protein (GFP). The GFP axolotl is a genetic modification of the albino axolotl that contains green fluorescent protein in its cells. GFP is a molecule that produces a bright green glow when exposed to ultraviolet light.

The GFP axolotl was originally used for research purposes because it allows scientists to observe its development without harming the animal. The GFP is one of the rarest axolotl and one of the most sought after from pet stores.

Can Axolotls Live with other Axolotls?

Axolotls are generally solitary creatures but can live with other axolotls that are approximately the same size in a large enough tank. Axolotls are social creatures but they are also territorial so each aquarium companion will need enough area to accommodate separate territories.

Axolotls can live with other fish if they are not aggressive and are a slow-moving species. It is generally not recommended to add fish to your axolotl tank in order to avoid stress to your axolotl from fish invading their territory.

How Big to Axolotls Get

A sexually mature adult axolotl averages between 9 and 12 inches in length from nose to tip of the tail at 18 to 24 months. The largest known axolotl grew to 18 inches long. In general, an adult axolotl weighs 10.5 ounces and are known for continued growth beyond sexual maturity under ideal conditions.

Axolotl Aquarium Requirements

Full-grown adult’s axolotl needs at minimum 10-gallon fish tank but ideally should have a 15-to-20-gallon fish tank. Even though the axolotl is an amphibian, a land area is unnecessary in the tank as they are fully aquatic animals. The water depth in your tank should be slightly more than the length of your axolotl but adding more water will give them more room to move around and improve the overall quality of the water.

The top of your tank should have a secure lid because they can jump several inches above the water level and get out of their enclosure. We recommend 3 to 4 inches of enclosure above the water level to keep them safely contained.

Axolotls love places to hide in pipes, artificial caves or bridges and they love living plants. These conditions provide comfort and contribute to stress-free living in your tank. It is not necessary for axolotl to have a substrate in your tank. A smooth aquarium bottom is easier to maintain but if you prefer to have gravel or glass pebbles the size should be larger than the axolotl’s adult sized head to prevent them from ingesting it.

Ideal Water Conditions for Axolotl

The ideal water for axolotls is brackish water. Brackish water is a mixture of fresh and salt water. Axolotls can survive in freshwater, but it is not the best water if you want to simulate the water from their natural habitat.

In general, you should always start with deionized distilled water, reverse osmoses water or at a minimum, water that has been cleaned through a carbon and particulate filter. Axolotls are sensitive to the alkalinity of water and need the water pH to remain between 6.5 and 7.5. The cleanest water you can use for your aquarium is distilled water, but the water is naturally acidic and will need to be treated to change the pH to a safe range for your axolotl. When using distilled water, treat the water in a separate container until the ideal pH is established before adding to your axolotl aquarium.

You can find water test kits, to include the pH testing solutions at most pet stores. For more helpful information on how to use your test kit please see our article on How to Test the Water in an Aquarium.

Axolotls need slow moving water in their aquarium because their gills can be easily damaged by high, rapid water flow. When choosing your filter make sure the features include an adjustable flow. To help you select the best filtration system for your aquarium setup please see our article on Which Fish Tank Filter is the Best. Our top recommendation for an axolotl aquarium is a sponge filter. They provide lots of bubbles to oxygenate your tank and they do not produce fast moving water.

The water should also be exposed to a (Ultraviolet) UV sanitization system to kill any harmful pathogens to prevent disease. To help you better understand the best use of a UV light sanitization system for your aquarium setup please see our article on Are UV Lights Good for Fish Tanks.

Warning: If tap water is used, we recommend you treat the water with a dechlorinate solution that does not have an aloe vera additive. Aloe Vera is toxic to axolotl and is sometimes added to dechlorinate water treatment chemicals.

For optimal health of your axolotl, we have a recipe (below) provided by German Axolotl researcher Johannes Holtfreter.

The solution is made as follows: Holtfreter’s Solution (per liter of water)
NaCl (salt – non-iodinized) 3.46 grams
KCl (potassium chloride) 0.05 grams
CaCl2 (calcium chloride) 0.1 grams
NaHCO3 (sodium bicarbonate) 0.2 grams

In their natural environment axolotl live in relatively cool lake water. When setting up your new habitat keep the tank in a cool room and away from bright sunlight. The water temperature should ideally be between 60 degrees and 64 degrees F (16-18 degrees Celsius). They can tolerate temperatures up to 74 degrees but sustained higher temperatures will cause stress, which leads to sickness, disease and even death.

Axolotl do not hibernate, so you don’t have to accommodate varying seasonal temperatures. In warmer climates you may even need to add a chiller to your tank to keep your water at the optimal temperature.

The last step in preparing the aquarium water for your axolotl to live in it is to “cycle” your water. In general, axolotl thrive when a healthy balance of nitrifying bacteria is growing in your tank. To cycle your water means to recreate the natural biological systems that exist in nature that convert ammonia (a byproduct of waste material) into nitrite and finally into nitrate, in your aquarium. On average this process takes 4 to 6 weeks from start to finish in a new aquarium. For helpful information on the cycling process please see our article on How to Setup an Aquarium. This article also covers how to shorten the cycling process through “seeding” strategies.

Once your water test kit shows your nitrate levels are stable, you will need to keep the levels low with regular water changes. You can enhance the stability of your water chemistry by adding live plants, but you will still need to change around 25% of your water at least once a week to ensure the removal of other harmful elements in your tank.

For more helpful strategies on maintaining ideal water chemistry please see our article How to Change Water in a Fish Tank. This is especially easy if your tank does not have gravel or any substrate on the bottom of your tank. If you are using gravel, then we recommend reading our article When to Clean Fish Tank Gravel.

Expert Tip: The most common cause of disease in axolotl is secondary to poor water quality. We recommend you test your water quality regularly to ensure a healthy and stable habitat.

Axolotl Feeding and Nutrition

Axolotls are slow and inactive most of the time but are carnivorous predators in the wild. They will lay immobile until their prey come close and then quickly snatch them up. In the wild an axolotl’s diet consists of snails, small fish and amphibians, crustaceans and worms. In captivity they will eat mostly bloodworms, earthworms, tubifex worms, and brine shrimp. You can transition them to pellet food, but many owners have difficulties moving them to an un-natural diet.

As juvenile’s axolotl in the wild eat one to two times a day, as they mature to adulthood, they will eat every two to three days. As you might expect the larger the axolotl becomes the larger the food sources are, and they often prefer the jumbo blood worms and adult earth worms at this stage of their development.

It is generally best to spread the feeding across the feeding day rather than one large feeding to help with their digestion and metabolism. One of the best methods to feed your axolotl is by dropping the food as close to them as possible. The best time of day for feeding is in the evening when axolotl are more active and generally display more predatory behaviors.

BEST PRACTICE: Remove any uneaten food from the axolotl aquarium every day to prevent ammonia spikes and stressful water conditions.

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