🦔

Sea urchin walks on its teeth

Have you ever seen a creature with no face, no eyes, and no tail—just a spiky ball on the bottom of the sea? It's a sea urchin. At first glance, it looks like an ordinary spiky rock. But inside this ball, there are real wonders.

The sea urchin has no head. But underneath, right in the center of its body, is a mouth with five hard "teeth." Scientists call this special mouth "Aristotle's lantern" - because 2,300 years ago, the ancient Greek scientist Aristotle described how it looked like an ancient lantern. The five teeth converge in the center and grow continuously throughout its life - they wear down on rocks and grow back again. With them, the urchin scrapes algae from the rocks like a tiny grater.

But how does a hedgehog walk if it doesn’t have legs? It does! Hundreds of tiny transparent legs-suction cups are hidden between the spines. With them, the hedgehog slowly walks along the bottom and even climbs onto rocks. And the spines themselves move - it can rotate each one individually, like thousands of small needle-antennae.

Some species of sea urchins live up to 200 years! They are the longest-lived among invertebrates. Imagine: a small spiky ball at the bottom saw how ships with sails sailed 200 years ago, how the seas and continents changed.

It's easy to mistake a hedgehog for a lifeless stone. But life beats inside it - ancient, slow, wise. Nature reminds us: beauty and miracles come in the most unexpected forms.