For many people, sharks are their worst nightmare – and anyone who has seen the film Jaws will understand this. In fact, only about 100 people are killed throughout the world each year and jellyfish are responsible for many more deaths.

Sharks are frightening because they are hunters though they do not normally hunt humans. Their prey is normally fish, seals or turtles and it is not really understood why they sometimes attack humans. It could be because the human is entering their territory or they could simply mistake the human for prey; they never normally eat a human they have attacked. A person on a surfboard can look like a turtle from underneath; a person in a wetsuit can look like a seal.

Sharks use their jaws to attack and to kill and their teeth are razor sharp. The shark’s jaw is lined with rows of pointed teeth, which are serrated on the sides and cut like a saw. These teeth are triangular in shape and point backwards towards the throat. Unlike humans, a shark never has a gap in its jaw. When it loses a tooth another one moves forward to replace it, so that during their lifetime a shark can have up to 30,000 teeth. During an attack a shark may lose several teeth and indeed shark’s teeth are often washed up on to beaches.

The shark has been around since dinosaurs roamed the earth. There are 350 different kinds and some are more dangerous than others, with the Great White the most feared.