Crabs are decapod crustaceans, meaning they have 10 legs, and are found in all the world’s oceans. There are over 4,500 species of crabs, making them one of the most diverse groups of animals on the planet. Crabs come in all shapes and sizes, from the tiny pea crab, which is only a few millimeters wide, to the giant Japanese spider crab, which can have a leg span of up to 12 feet.
Crabs are an important part of the marine ecosystem. They are scavengers, and they help to clean up the ocean floor. They are also a food source for many other animals, including fish, birds, and mammals.