10 Things You Didn't Know About Sea Urchins

Here are 10 things you probably didn't know about their surprisingly somewhat-complex lives of sea urchins.

"Is this a predation event that we are witnessing? We might be witnessing some deep-sea predation here." [NOAA]

Ah, the life of a sea urchin. Just floating around in the ocean and...

What do sea urchins do, anyway?

Here are 10 things you probably didn't know about their surprisingly somewhat-complex lives.

Number 10. Some hang around for a long time. The red variety can live for about 200 years, making them among the longest lasting creatures on Earth. That means it's entirely possible that there's still an urchin out there who crossed paths with Lewis & Clark.

Number 9. They don't have brains. The movements of their tubular feet are controlled by a simple nerve ring. It's relatively small, and most of their interior space is filled with digestive, water-carrying, and reproductive organs.

Number 8. Sea urchins have teeth which come together and form a beak of sorts called an Aristotle's lantern.
"Each urchin has 5 teeth which are self-sharpening and are replaced every few months." [BBC]

Number 7. Being prickly isn't their only line of defense. Sea urchins can also use their spines to burrow into small rock enclosures when extra safety measures are required.

Number 6. Their spines are also light sensitive. That's how they get a sense of where they are. In fact, their ability to differentiate between varying intensities of bright and dark is so sensitive, it gives them visual abilities equal to some sea creature that have eyes.

Number 5. Sea urchins reproduce in groups. The process starts with males releasing sperm into the water. Then, the females come along and throw some eggs into the mix. When the two combine, a baby sea urchin will soon enter the world.

Number 4. Our planet may be saved by them. Well, by studying and mimicking them, anyway. When sea urchins create their exoskeletons they use nickel ions to trap the carbon dioxide needed for its development. Scientists are currently testing how effective nickel nanoparticles are at converting larger amounts of CO2 into carbonate.

Number 3. They're highly sought-after snacks. Oceans are filled with creatures looking to feast on sea urchins. Among them are sea otters, wolf eels, octopuses, and triggerfish.

Number 2. Humans like them too. Some people even eat sea urchins while they're still alive, cutting them open with a pair of scissors and slurping out their insides.

Number 1. Sea urchins are excellent judges of water quality. When water starts to go bad, they're among the first creatures to react to its diminishing condition. Telltale behaviors include the collapsing of spines, slowed movement, and, sadly, death.