dozens of horseshoe crabs come ashore on a beach
Horseshoe crabs take over a Delaware beach, photo by the U.S. Fish and Wildlife Service via Flickr (CC BY 2.0).

If you’ve ever gotten a medication injected or had a medical device implanted (think artificial knee replacement), you owe a debt of gratitude to the horseshoe crab, whose bright blue blood is a magic bacteria-finding beacon used to detect sterilization-resistant toxins in injectables and implantables.

How do we get all this crab blood? By catching crabs, draining a third of their blood, and tossing them back into the sea. Is this sustainable? No one really knows, yet — but hopefully, we will soon. Caren Chesler, in Popular Mechanics, explores the plight of the humble horseshoe and the researchers trying to help.

To that end, these two scientists are putting this strange catch to the test. The pair took 28 horseshoe crabs from the Great Bay Estuary behind their lab, left them out in the heat, then drove them around in a car for four hours and then left them in containers overnight to simulate what might happen in a bleeding facility. Then they bled half the crabs (so they’d have a control group that wasn’t bled). All of the crabs remained in containers a second night, as would likely happen at a bleeding lab. The following day, Owings and Watson put $350 transmitters on their backs, attached them snugly with little zip ties, and put the crabs back into the bay to see if they could make their way. What they find might have a lot to say about the future of this odd routine.

Read the story