Will an Axolotl Eat My Fish?

The short answer is yes, an axolotl will very likely eat your fish if given the opportunity. Axolotls are carnivorous amphibians with a natural instinct to hunt and consume smaller creatures. While their vision isn’t the best, they rely on movement and chemical cues to locate prey. Therefore, any fish small enough to fit in an axolotl’s mouth is a potential meal. Housing fish with axolotls is generally strongly discouraged due to this predatory behavior.

Understanding Axolotl Predatory Behavior

Axolotls, scientifically known as Ambystoma mexicanum, are native to the lake system of Xochimilco near Mexico City. In their natural habitat, they prey on various invertebrates, small fish, and insects. This ingrained hunting behavior persists even in captivity.

Axolotl Diet in Captivity

In captivity, axolotls are typically fed a diet of earthworms, bloodworms, blackworms, and commercially available axolotl pellets. However, their opportunistic nature means they will readily consume any available protein source, including fish.

Factors Influencing Predation

Several factors influence the likelihood of an axolotl preying on fish:

• Size of the Fish: The most significant factor is the size difference between the axolotl and the fish. Smaller fish are easier to catch and swallow.
• Axolotl Size: Larger axolotls are capable of consuming larger fish.
• Swimming Speed and Agility of the Fish: Slower, less agile fish are easier targets. Fish with long, flowing fins (like guppies) can be tempting and easily nipped.
• Tank Environment: A sparsely decorated tank with limited hiding places makes it easier for the axolotl to hunt.
• Feeding Schedule: A well-fed axolotl might be less inclined to hunt, but this isn’t a guarantee. An axolotl that is hungry is far more likely to actively hunt any fish in its tank.
• Species of Fish: Some fish are naturally more docile and less likely to evade predation.

Why Cohabitation is Problematic

Beyond the risk of the axolotl eating the fish, keeping fish with axolotls presents other serious problems.

Risk to the Fish

• Stress: Even if the fish isn’t immediately eaten, being constantly pursued by a predator can cause chronic stress, weakening their immune system and making them susceptible to disease.
• Injury: Axolotls might attempt to eat fish that are too large, leading to injuries for both the axolotl and the fish.
• Fin Nipping: Axolotls may nip at the fins of fish, causing damage and potential infection.

Risk to the Axolotl

• Disease Transmission: Fish can carry parasites and diseases that can be harmful or even fatal to axolotls.
• Ingestion of Gravel or Substrate: When an axolotl snaps at a fish near the bottom of the tank, it may accidentally ingest gravel or substrate, leading to impaction and health problems.
• Nutritional Imbalance: Fish are not a complete and balanced diet for axolotls. Relying on fish as a primary food source can lead to nutritional deficiencies.

Species Selection for Cohabitation: A Myth

There is no fish species that can be reliably and safely cohabitated with axolotls. Some hobbyists may claim that certain fish are “axolotl-safe,” but this is usually based on anecdotal evidence or temporary success. Even seemingly peaceful fish can nip at the axolotl’s gills or slime coat, causing irritation and infection. The lower temperatures that axolotls prefer are also stressful for many fish species, weakening their immune system and making them more susceptible to disease. Ultimately, separating axolotls and fish is the best practice for the well-being of both animals.

What to Do If You’ve Already Cohabitated Axolotls and Fish

If you are currently keeping fish with your axolotl, the best course of action is to separate them immediately. Set up a separate tank for the fish, ensuring it is properly cycled and provides a suitable environment for the fish species. Monitor both the axolotl and the fish for any signs of stress or injury.

Frequently Asked Questions (FAQs)

1. Can I keep feeder fish with my axolotl as a treat?

No. While it might seem like a natural treat, feeder fish can carry diseases and parasites that are harmful to axolotls. There are much safer and healthier alternatives for providing enrichment, such as offering different types of worms or axolotl pellets.

2. What if the fish are too big for the axolotl to eat?

Even if the fish are too large to swallow whole, the axolotl might still nip at their fins or attempt to injure them. This can cause stress and injury to the fish. Furthermore, a determined axolotl might eventually be able to injure a larger fish significantly.

3. My fish and axolotl have been living together for a long time without any problems. Does this mean it’s safe?

Even if there haven’t been any apparent issues so far, the potential risks remain. The axolotl could suddenly decide to prey on the fish, or the fish could develop a disease that is transmitted to the axolotl. It’s always best to err on the side of caution and separate them.

4. Can I keep shrimp or snails with my axolotl?

While some hobbyists have success keeping certain types of shrimp or snails with axolotls, it’s not always guaranteed. Axolotls may eat smaller shrimp and snails. Larger snails with hard shells might be a better option, but even they could be harassed or injured by the axolotl. Proceed with caution and monitor the situation closely.

5. What are the best tank mates for axolotls?

Axolotls are best kept alone. They are not social creatures and do not require tank mates. Keeping them in a species-only tank eliminates the risks associated with cohabitation.

6. Will an axolotl eat aquatic plants?

No, axolotls do not typically eat aquatic plants. They are carnivores and have no interest in vegetation. However, they may uproot plants while hunting or moving around the tank.

7. What size tank is appropriate for an axolotl?

A 20-gallon long tank is generally considered the minimum size for a single adult axolotl. Larger tanks are always preferable, providing more space for the axolotl to move around and explore.

8. What are the ideal water parameters for axolotls?

Axolotls require cool, clean water. The ideal temperature range is 60-68°F (16-20°C). The pH should be between 6.5 and 7.5. Ammonia and nitrite levels should be 0 ppm, and nitrate levels should be kept below 20 ppm.

9. How often should I feed my axolotl?

Young axolotls should be fed daily, while adult axolotls can be fed every other day. Adjust the amount of food based on the axolotl’s size and appetite.

10. What are the signs of a healthy axolotl?

A healthy axolotl will have clear skin, bright eyes, and healthy gills. It will be active and responsive and will have a good appetite.

11. What are some common health problems in axolotls?

Common health problems in axolotls include fungal infections, bacterial infections, impaction, and stress. Maintaining proper water parameters and providing a clean environment can help prevent these problems.

12. Can I keep more than one axolotl in the same tank?

Yes, axolotls can be kept together as long as they are of similar size. It’s important to provide ample space and hiding places to prevent aggression. Very small axolotls should not be kept with significantly larger ones, to avoid the risk of cannibalism.

13. What type of substrate is best for axolotls?

Fine sand is generally considered the best substrate for axolotls. It is easy to clean and poses a minimal risk of impaction. Bare-bottom tanks are also an option, but they can be less aesthetically pleasing. Avoid using gravel, as it can be easily ingested and cause impaction.

14. How do I cycle an axolotl tank?

Cycling an axolotl tank is the same as cycling any other aquarium. It involves establishing a beneficial bacteria colony that converts harmful ammonia and nitrite into less harmful nitrate. This can be done using fish food or pure ammonia as a source of ammonia.

15. Where can I buy an axolotl?

Axolotls can be purchased from reputable breeders, pet stores, or online retailers. Always research the seller and ensure they are providing healthy, ethically sourced animals. Avoid buying axolotls from sources that do not prioritize their welfare.