How Axolotls Regrow Entire Limbs From Scratch
The axolotl can regenerate lost legs, its spinal cord, and even parts of its brain. Here's what scientists have learned about how this salamander does it.
Most animals that lose a limb are stuck without it for life. The axolotl is a striking exception: this small Mexican salamander can regrow an entire missing leg, section of tail, or piece of its heart, and it does so without forming scar tissue.
What Makes the Axolotl So Unusual
Axolotls are native to a single location on Earth, the canal system of Lake Xochimilco near Mexico City. Unlike most amphibians, they stay in their juvenile, aquatic form for their entire lives instead of transforming into a land-dwelling adult, a trait called neoteny. That youthful state may be part of what keeps their regenerative machinery switched on.
According to National Geographic, axolotls can regrow lost or damaged limbs, hearts, spinal cords, and even parts of their brains, all without permanent scarring.
How Regeneration Actually Works
When an axolotl loses a limb, cells at the wound site form a mass called a blastema. This blastema effectively “remembers” what body part was lost and regrows exactly that piece, whether it’s an entire leg or just a missing toe.
Recent research has zeroed in on the chemistry behind this process. A 2025 study covered by Smithsonian Magazine found that a molecule called retinoic acid, combined with a gene called Shox, tells the axolotl’s cells exactly what to rebuild and where. When scientists used CRISPR gene editing to remove the Shox gene, the axolotls grew normal hands but abnormally short arms, showing just how precisely this signaling controls the outcome.
Why Axolotls Don’t Scar
In humans, injured tissue often heals by forming scar tissue, which is faster but permanently blocks regeneration. Axolotls take a different path. Special cells called glial cells repair damaged nerve tissue directly instead of scarring over it, a process explained by National Geographic’s coverage of regeneration research. Scientists studying this difference hope it could eventually help treat human spinal cord injuries.
Why This Matters for Human Medicine
Humans and axolotls share many of the same genes involved in this process, including the Shox gene and the retinoic acid pathway. Researchers believe the difference isn’t that humans lack the tools for regeneration, it’s that those tools aren’t switched on the same way after an injury.
As one researcher told National Geographic, a better understanding of how these amphibians grow new appendages may lead to better wound healing, or even new limbs, in humans one day. Scientists caution that this remains a long-term goal rather than an imminent breakthrough.
Conservation Status
Despite their popularity in the pet trade and in labs worldwide, wild axolotls are critically endangered. Pollution, urban expansion, and invasive species have devastated their only natural habitat in Lake Xochimilco. Ironically, one of science’s most valuable research animals may not survive in the wild much longer without dedicated conservation efforts.
Frequently Asked Questions
Can axolotls regrow any body part? They can regenerate limbs, portions of the spinal cord, heart tissue, and parts of the brain, though not every organ regenerates equally well.
Are axolotls the only animals that can do this? No, but they’re one of the most capable. Other salamanders share some regenerative ability, but axolotls are unusually good at regrowing complex structures without scarring.
The axolotl’s ability to simply regrow what it loses continues to reshape how scientists think about healing, and it may one day change how human medicine approaches injury altogether.
Related Articles
Can Axolotls Really Regrow Their Brains?
Axolotls don't just regrow legs and tails — they can rebuild damaged sections of their own brain. Here's what scientists have found about how far that ability really goes.
What Animal Has the Strongest Bite Force?
Saltwater crocodiles hold the record for the strongest bite force ever directly measured in a living animal. Here's how scientists measured it, and how it stacks up against lions, hippos, and great whites.
How Does Bioluminescence Work in Animals?
From anglerfish lures to glowing plankton, most of the light produced in the ocean comes from a single chemical reaction. Here's how bioluminescence actually works, and why so many animals rely on it.
_male_Nosy_Be.jpg)
Why Do Chameleons Change Colour?
Chameleons don't change color for camouflage the way most people assume. The real mechanism involves nanocrystals in their skin, and the real reason is mostly about communication.
How Do Electric Eels Generate Electricity?
Electric eels can deliver shocks of several hundred volts using nothing but modified muscle cells wired together like a living battery. Here's how the biology behind it actually works.
Why Are Pangolins the Most Trafficked Mammal?
Pangolins are the only mammals covered entirely in scales, and that single trait has made them the most heavily trafficked mammal on Earth. Here's why, and what's being done to protect them.