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. Lesson by Carly Anne York, animation by Jérémie Balais and Reza Riahi.