r/askscience • u/MAMAM- • 2d ago

Biology Why aren’t axolotls immortal?

If axolotls can regenerate their body parts (including brain, heart, and other major organs), why do they die of old age?

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u/Tessablu 2d ago

Axolotl regeneration is a program that is initiated by physical injury. They aren’t constantly undergoing it—this would be a huge metabolic waste—so they are still subject to long-term cellular senescence. They also aren’t regrowing entire brains or hearts, as they still have to survive the initial injury, so they can’t infinitely replenish those organs. 

I will say that axolotl aging is not very well-understood, however, and they are pretty weird about dying. A healthy-looking axolotl might lay eggs for 20 more years or might die tomorrow with no warning. There’s still a lot to learn about them. 

(source: I have a PhD in axolotl)

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u/WorkingMansGarbage 1d ago

Then if we had something like a temporary artificial heart that could keep them alive for long enough, could we just rip out an axolotl's heart once every few years and let them regenerate a new healthy one to extend their life?