Injury or missing limb, kept with other axolotls
This looks like: injury from another axolotl (or fish, if any are present) — regeneration will likely handle the physical repair, but the cause needs addressing
Why this happens
Axolotls, especially juveniles, do nip at each other's limbs and gills, and any fish sharing the tank pose a similar risk. The good news is genuine limb and gill regeneration — the bad news is that repeated injury from an ongoing aggression source is a real stress and infection burden, not something to just let keep happening because it grows back.
What to do right now
- Separate the injured axolotl into its own tank while it heals — this protects it from further injury and reduces infection risk.
- Keep the water especially clean during recovery — regenerating tissue is vulnerable to infection until it's closed over.
- Reassess the original tank setup: axolotls housed together should be a similar size, and even then, some pairs simply don't get along and need permanent separation.
- If fish are present in that tank, this is also a sign to remove them — see our guide on axolotl tank mates for why fish and axolotls don't mix safely.
- Watch the wound over the following weeks — clean, gradual regrowth is normal; redness, swelling, or no progress after a couple of weeks is worth a vet check.
What not to do
- Don't put the same animals back together assuming it was a one-off — repeat aggression is common once it's started, especially with a size mismatch.
Stop it happening again
Only house similarly-sized axolotls together, watch new pairings closely, and separate permanently at the first sign of repeated aggression.
If that doesn't fix it
Regeneration typically takes weeks to a few months depending on what was lost — track healing progress rather than expecting it back to normal quickly, and keep the pairing separated in the meantime.
Catch this earlier next time — log your axolotl's water parameters in App-aquatic. Free forever.
This isn't veterinary advice - it's a directional read to help you decide your next step, based on the most common causes and independently checked sources (Merck Veterinary Manual, PetMD, established amphibian husbandry references). We can't see your axolotl, so pair it with a liquid test kit and clear photos, and see an exotic or aquatic vet for anything serious or not improving.