Horseshoe crabs show up in the fossil record over 445 million years ago. Their blood is valuable in testing vaccines.

Horseshoe crabs are not endangered or threatened in Massachusetts, but their numbers are at historic lows. To protect the species, state wildlife officials are rolling out new regulations. As of 2024, ...

Forbes contributors publish independent expert analyses and insights. I write about biodiversity and the hidden quirks of the natural world. With copper-blue blood prized by modern medicine and a body ...

Horseshoe crabs have weird blood, mate en masse in May and June, and harbor a secret weapon that’s probably saved your life. Here are some more facts about these ancient arthropods. In fact, they aren ...

Celebrate World Ocean Day on June 8 by learning about these ancient arthropods Ashley Goetz The ocean has many unusual inhabitants, but few are as strange and ancient as the horseshoe crab. Get to ...