Inside the Steel Jaws of a Great White Shark

Great white sharks (otherwise known as great whites or white pointers) are famous for their distinctive fins and ferocious teeth! This apex predator needs impressive dentition to catch and eat prey in waters where it competes with other animals for food. But what are shark teeth made of, and how do they use them? You will discover this and a lot more about shark teeth right here.

Great White Shark Distribution and Diet

These sharks are found worldwide in temperate and subtropical waters and often migrate seasonally. In the U.S., they can be found in the Atlantic Ocean from Maine to the Gulf of Mexico and the U.S. Caribbean, as well as in the Pacific Ocean from Alaska to California and Hawaii. Younger sharks are usually found nearer the shore, but mature individuals are also seen in offshore pelagic waters.

These are large animals – at maturity, they can reach 20 feet in length and can weigh over 4,000 pounds. To maintain this huge body, they eat about 0.5 to 3 percent of their total body weight per day. For an average weight of 2,750 pounds, this equates to 13.75 to 82.5 pounds of meat per day. They are opportunistic feeders who are willing to feed on a wide range of fish, marine invertebrates, and mammals. Juvenile great whites hunt bottom fish, smaller sharks, small rays, schooling fish, and squids. The adults can tackle seal and sea lion colonies and sometimes scavenge on whale carcasses. To catch, kill, and consume this type of prey, they need strong jaws and teeth.

Great White Shark Jaws and Bite Force

This shark’s jaws are reinforced by layers of tough mineralized cartilage. Furthermore, their jaw muscles are arranged in a unique way that allows them to exert a very high bite force no matter how wide their mouth is open. This means they can powerfully bite down on prey of all sizes. Their upper and lower jaw muscles are divided by a tendon that pulls the muscle fibers straight and perpendicular to the jaw as the mouth opens. Using digital reconstruction models, scientists predict that the maximum bite force of a great white may reach 18,000 Newtons (4,000 pounds), amongst the highest known for any living species.

However, this phenomenal bite strength takes years to develop. Younger sharks have surprisingly weak jaws and would not be able to bite a chunk off a sea lion. Their jaws only strengthen once they reach about 10 feet in length, and their diet changes. What’s more, juvenile white sharks have a subterminal mouth (the lower jaw is shorter than the upper jaw and the opening is pointing downward), which is most effective for eating crustaceans and fish near the bottom. The adult’s mouths, however, are more terminal (pointing forward) and are better suited for grasping sea mammals.

Great White Shark Teeth

Great white sharks rely on their teeth for survival from a very young age. They are born with teeth, and studies have found that even shark embryos have teeth. They are formed from specialized skin tissue on the jaw cartilage. Great white teeth are arranged in rows and attached to the jaws by connective tissue. They are made from a very hard substance called enameloid covering a core of dentine (apatite and collagen).

There are up to 28 exposed teeth in the upper jaw and up to 25 in the lower jaw, for about 50 visible teeth at any time. However, below their gums, there are a lot more! Their ‘spare’ teeth are developing, folded back against the inside of the jaw. They are connected by collagenous and fibrous tissue and are not fixed into bone as in humans and many other mammals. When a tooth is lost, another emerges from the gum to take its place. They can get through thousands of teeth in their lifetime. This process is called polyphyodonty and has been described as a conveyor belt. A great white shark can have around 300 teeth in total.

Juvenile shark teeth are pointed—just the right shape for grasping smaller prey, such as crustaceans, that can be swallowed whole. Adults, however, feed on sea lions and seals, and these cannot be swallowed whole. So, they have serrated, flat, triangular teeth that they can use for seizing prey. They use these deadly teeth to great effect, stripping fat and muscle from their prey’s bodies. They often release their prey several times, consuming it in multiple bites. When a shark opens its mouth, its teeth (especially on the upper jaw) are moved forward by connective tissue. As the jaw closes, the teeth are pulled back into a thick sheet of dental ligament and connective tissue.