The animals are drained of some in their blood and returned to the setting, but lots of die from the bleeding. Its blue blood is harvested for medical scientists and used by drug and medical product makers to test for dangerous impurities in vaccines, prosthetics and intravenous drugs. Conservation groups https://horseshoe-crab-blood-for75295.digitollblog.com/30060923/little-known-facts-about-horseshoe-crab-blue-blood