Sharks have adapted to their marine environments in a number of ways, including the development of sophisticated gills, allowing them to remain underwater without having to come up for air, and a streamlined body with fins, enabling rapid and efficient movement beneath the waves. They are also well adapted as predators, with many razor sharp teeth that grow back almost instantaneously when lost.
Sharks' skin is also particularly tough, protected by an array of sharp and continually replenished scales known as dermal denticles. In addition to offering sharks protection, their skin also facilitates rapid and stealthy movement through the water.
Sharks' jaws are not attached to their skulls via bone, an adaptation which allows sharks to push their jaws out from their heads in order to suck in prey.
Sharks are also highly specialized for sensory perception, able to detect the electrical signals of their prey with organs known as ampullae of Lorenzini. They can also track prey by using the highly sensitive vibration detectors running the length of their bodies.
Great white sharks are known for their white bellies, contrasted by their dark backs. Known as "countershading," this adaptation serves as camouflage, making it hard for other fish to differentiate the sharks from sunlight when below, or the seabed when above.