Scholastic asserts that sharks are especially well adapted to an ocean environment due to their physical features, such as streamlined bodies for efficient swimming, rows of sharp teeth that grow back after they fall out and gills that extract oxygen from the water so they do not have to surface to breathe. Sharks live in all of Earth's oceans and migrate to find food.
Defenders of Wildlife points out that sharks' bones are made of cartilage, which makes their bodies lighter. Accordingly, their muscular bodies swim faster than bony fish. Shark skin is made of hydrodynamic scales that also act as a skeleton that conserves energy in the water. The lower side of sharks are light-colored to camouflage their bodies so that predators have trouble seeing them from below, according to Defenders of Wildlife.
Sharks have adapted to various ocean environments. The predators live in open ocean, shallow coastal regions and on the ocean floor. Sharks-World points out that some species, such as the bull shark, can live in saltwater, freshwater and brackish water.
Defenders of Wildlife notes that there are 465 known species of sharks. These creatures are apex predators that consume a wide range of food including fish, mollusks, plankton, crustaceans, marine mammals and even other sharks. A shark's sense of smell can detect blood in the water from more than a mile away, which is a useful adaptation for hunting in the world's oceans.