Sitting right at the top of the marine food chain, sharks fall into the scientific superorder Selachimorpha. Beneath this, there are 14 or so 'orders' but a simpler way to describe their diversity is to state that there are 440 different species of shark in our oceans. These amazing animals vary from the deep sea dwarf lanternshark, which measures just 17 centimetres (7 in) long, to the majestic and placid whale shark (or whaleshark), Rhincodon typus, which can reach as much as 12 metres (39 ft).
Sharks are found in all seas and some travel to depths of 2,000 metres, sometimes more. The Great White shark and the hammerhead sit at the very top of the apex predator chain while others, like basking sharks are completely harmless.
Conservation
While sharks are seen as the ultimate predators, their survival continues to be threatened by man and in particular, by commercial fishing practices. It is estimated that 100 million sharks are killed every year in this way.
For more information on shark conservation projects, http://www.sharktrust.org/