The Axolotl Shouldn't Exist (12 Insane Facts)

[00:00:00]Cut off its leg — it grows a new one.

[00:00:02]Damage its heart — it rebuilds it.

[00:00:05]Cut into its brain — yeah, that comes back too.

[00:00:08]This is the axolotl, and it might be the single most impossible animal alive.

[00:00:15]Twelve facts.

[00:00:17]Let's go.

[00:00:18]Fact one: it never grows up.

[00:00:20]Every other salamander loses its gills and crawls onto land.

[00:00:24]The axolotl just… refuses.

[00:00:27]It keeps those feathery gills and that upturned mouth its whole life — which is why it always looks like it's smiling.

[00:00:34]It's basically a permanent baby.

[00:00:36]Fact two: that smile is on a body about the size of your hand — six to twelve inches of pure weird.

[00:00:45]Fact three: it comes in a whole rainbow.

[00:00:48]Wild ones are dark and mottled.

[00:00:51]Pet ones are that famous bubblegum pink.

[00:00:53]There are golden albinos, and jet-black ones called melanoids.

[00:00:58]And fact four — this one's real — scientists have engineered axolotls that glow.

[00:01:04]Fluorescent green, under UV light.

[00:01:07]A living, regenerating, glow-in-the-dark salamander.

[00:01:11]But the regrowth is the main event.

[00:01:14]Fact five: where you'd form a scar, it forms a blastema — its own cells rewind to an embryonic state and rebuild the whole limb, bone, muscle and nerve, in about a month.

[00:01:27]Fact six: nearly half of that new limb is built from skin cells.

[00:01:33]Fact seven: no nerve, no regrowth — cut the nerve and it just stops.

[00:01:39]Not a patch.

[00:01:40]A perfect replacement, every time.

[00:01:43]Fact eight — how do the cells know what to build?

[00:01:47]They use a chemical GPS.

[00:01:48]A gradient of retinoic acid runs along the limb: high at the shoulder, low at the hand.

[00:01:55]Each cell reads its position and builds exactly what belongs there.

[00:02:00]Fact nine: in twenty-twenty-five scientists found a gene behind it — shox — and it's the same gene that sets human height.

[00:02:10]The same instruction, running in them and in us.

[00:02:14]And it doesn't stop at limbs — this is fact ten, and it's the wild one.

[00:02:19]The axolotl regrows its spinal cord and walks away.

[00:02:23]It rebuilds heart tissue with no scar.

[00:02:26]It regenerates parts of its brain.

[00:02:29]Researchers have even transplanted eyes and pieces of brain into one and watched it wire them in and switch them on.

[00:02:39]Almost anywhere you break it — it just… rebuilds.

[00:02:43]Which makes fact eleven the cruel one.

[00:02:45]The animal that can't be killed by injury is nearly gone from the wild.

[00:02:50]In its only home, a lake under Mexico City, numbers crashed from six thousand per square kilometre to basically zero in fifteen years.

[00:02:59]Fact twelve: almost every axolotl on Earth descends from under thirty-six animals.

[00:03:05]It beat injury — but it might not beat us.

[00:03:08]So if this little smiling alien amazed you even once — subscribe.

[00:03:13]Next impossible animal drops soon.