At first sight, all these creatures have nothing in common whatsoever. But in reality, all of them are sharks! There are more than 500 shark species in the world, and lots of them don’t look as if they’re related. The most fearsome predators in the ocean, sharks have been around for more than 400 million years. They have adapted to all kinds of tough conditions. Most people would probably feel more comfortable without sharks lurking in the ocean depths. So what if there were no sharks? What would the oceans look like if all of the sharks disappeared? (Spoiler: That would turn into a disaster for our planet.)