Conservationists fear that horseshoe crabs, a 450-million-year-old living fossil, will be pushed to the brink of extinction because of the value of their blood to the pharmaceutical industry. Horseshoe crab blood provides a natural source of limulus amebocyte lysate (LAL) which is used to test vaccines, drugs, and medical devices to ensure that they aren’t contaminated with dangerous bacterial toxins called endotoxins. With hundreds of thousands of horseshoe crabs captured and bled of their milky-blue blood each year, conservation groups are now stepping up their advocacy efforts and taking legal action to help save horseshoe crabs and the other species that rely on them.
Image: Horseshoe crabs are bled at the Charles River Laboratory in South Carolina. Timothy Fadek