Horseshoe crab

Horseshoe citizen scientist classes may be popular among environmentalists just caring for nature, but less well known is how much the creatures do for humans: a compound in the animal's blue blood has the unique ability to ensure the safety of vaccines, injectable medications, and medical devices

Horseshoe crabs' blood can detect bacteria and it is under threat in South Florida by habitat loss, red tide, and pollution so scientists are asking beachgoers to help.