Sharks' teeth can grow back if they are lost. If you rub along a shark towards the tail, it feels smooth, but if you rub the other way, it is rough.
Sharks have skin covered in millions of tiny teeth-like scales that point to the tail. Every inch of tooth equals 10ft of shark length: so if a shark tooth is 2 inches long, the tooth came from a shark that was 20 ft long! Even more terrifying is that some of the Megalodon teeth are 6 inches long so that suggests a shark 60 feet long. First, they measure the length of the tooth in inches. Shark teeth collectors can guess how large a shark was by measuring the shark tooth. Because there are so many different kinds of sharks, and because each kind has its own kind of special teeth, many people enjoy collecting shark teeth. For instance, some sharks have sharp, pointy teeth, while bottom dwelling sharks have cone-shaped teeth for crushing shells. Sharks have different-shaped teeth, depending on what they eat. This is why a shark does not eat every day. This is pretty slow, however, so a meal might take several days to digest. The chunks of food that a shark swallows end up in its stomach, where they are digested. So they bite their prey and jerk it around so they can pull off a chunk to swallow. In its lifetime, a shark can lose and regrow as many as 30,000 teeth.Įven with all those teeth, though, sharks can not chew. Sharks eat so violently they often break a few teeth, so new teeth grow continuously in a groove just inside the mouth and move forward from inside the mouth on "conveyor belts" formed by the skin which they are attached to. Their teeth are constantly replaced throughout their lives. Sharks come in many different shapes and sizes, but most are long and thin (also called streamlined), with really strong jaws. Most sharks are cold-blooded but some, like the great white shark and the mako shark are partially warm-blooded.Ĭharacteristics Some common kinds of shark are the hammerhead shark, the great white shark, the tiger shark, and the mako shark. However, a recent study shows that sharks emit a low growl from their throats which resonates through their scales. It is widely believed that sharks are "silent killers".
This is the whale shark, the largest fish in the world. However, the largest shark eats krill, like whales. Most sharks are predators: they hunt and eat fish, marine mammals, and other sea creatures. Fossils show that sharks have been around for 420 million years, since the early Silurian. There are more than 350 different kinds of sharks, such as the great white and whale sharks. Cartilaginous fish also include skates and rays. Cartilage is tough, rubbery material which is less rigid than bone. They, like other Chondrichthyes, have skeletons made of cartilage instead of bone. Sharks are a superorder of fish, the Selachimorpha.