Jellyfish have been swimming in our oceans for well over half a billion years, longer than any other animal that lives on the planet. They make a venom so toxic it can kill a human in three minutes. Their sting—microscopic spears that pierce with five million times the acceleration of gravity—is the fastest known motion in the animal kingdom. Made of roughly 95 percent water, some jellies are barely perceptible virtuosos of disguise, while others glow with a lumines... >Voir plus