(via TEDEd) There are about 500 species of squid, and they live in all the world’s oceans, making them a reliable food source for whales, dolphins, sharks, seabirds, fish - and even other squid. As a result, the squid's most extraordinary adaptations are those that have evolved to help them thwart these predators. Carly Anne York explains how these stealthy cephalopods have mastered deep sea survival.