At over 45 feet, it's also the world's largest fish. The whale shark strains out tiny animals that drift in the sea, such as plankton, shrimp, and small fish. The smallest shark is the spined pygmy shark. It's less than 10 inches long and can be found in the cold, deep oceans. It's bioluminescent which means it glows in the dark.
Most sharks are efficient swimmers.
The highly streamlined mako has been clocked at speeds up to 22 mph. Sharks are highly-specialized predators, with sharp teeth, strong jaws, streamlined bodies, and powerful senses. Even today, of the over 350 different shark species, fewer than ten are considered dangerous to humans. There are almost six billion people on our planet, and less than ten people are killed by sharks each year. Sharks and shark by-products are important resources.