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All About Limlus Polyphemus AKA The Horseshoe Crab

woman holding two horseshoe crabs while standing at the beach

Have you ever seen crabs crawling around on the beach? They're called limlus polyphemus, commonly known as a horseshoe crab.


Actually, the name is a misnomer. It's not a crab, or even closely related to crabs. It's not closely related to anything else in the sea, though it is a distant relative of spiders. Horseshoe crabs are arthropods; invertebrates with jointed legs, segmented bodies and external skeletons.

They're incredibly hardy creatures: they can go without food for an entire year and survive radiation that would kill a human being. They've been on earth for a long, long time.

How Much Radiation?

About four hundred and seventy five million years, in fact. They evolved from a now-extinct species of giant water scorpion that existed some five hundred and fifty million years ago. And it grew to several feet in length!

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