Horseshoe crabs have been on Earth for an estimated 450 million years, but humans might be decimating their population because, to borrow a line from Dracula, we vant to suck their blood.
The bright blue blood that runs through these tiny creatures has incredible biomedical properties that can work as an E. coli detector, which is why horseshoe crab blood can cost as much as $14,000 a quart. The unique chemicals in their blood can be used to test for dangerous bacteria in injectable drugs, implantable medical devices, and hospital instruments. Due to this nearly magical property, horseshoe crabs are harvested by the thousands, forced to donate blood, and then, with no cookie or tiny cup of orange juice, chucked back into the sea—and no one knows whether or not they recover from the process.
Read the full, weird story over at Popular Mechanics while you think about what it would be like if this situation were reversed and horseshoe crabs were doing this to humans.