Sharks Did you know that sharks are carnivores? That means they eat meat. They have 5-7 gill slits which help them breathe. Their teeth can easily slice through flesh. The Mako Shark is the fastest shark. It can swim 60-90 miles per hour. Different species have different tail shapes. Sharks must swim constantly to keep them from sinking. They have a cartilage skeleton. It is made out of the same materials as your fingernails. Inside their mouths there is over 3,000 teeth. Their skin is as rough as sand paper. It may also have marbling spots or bands. It has sense pores on its nose.Sharks love to hunt already injured animals. They chow down on fish, crabs, lobsters, squid, eels and an octopus. They can detect sound waves. They can also sense electric and magnetic fields. They can smell one drop of blood in one million drops of water. They have very powerful jaws. Sharks can get into feeding frenzies and rip each other to pieces. They are very high in the food chain. Sharks can vomit anything from their stomach at will.Humans have killed 100 million sharks in one year. Shark skin is used as leather and their meat is sold, even though they are usually not harmful to humans. Shark attacks are pretty rare. The largest sharks are harmless. Interactions between sharks and humans are classified into three primary categories: Encounters, provoked , and unprovoked. Encounter: A shark encounter is a coming together of a shark and a human where neither gets hurt. The shark swims around the human and examines the human. Provoked: A provoked shark attack is when the human does something to annoy the shark and the shark fights back. Unprovoked: An unprovoked shark attack is when the shark attacks without the human having done anything.I bet you didn't know that the first sharks lived about 300 million years ago. The sharks here today appeared 100 million years ago. There are 375 different species of shark. Maybe even more!! Less than 30 species of shark are dangerous, so if you see one no harm will come to you unless you die of fright!! Most sharks live alone. The Whale shark is 50 feet long. Sharks all live in salt water.