All sharks eat fish. Nearly 1,000 tons of water per hour passes by the enormous gills of the basking shark when it's feeding. Sharks are unpredictable. Researchers have discovered, for example, that the grey reef shark exhibits a distinctive behaviour when threatened. It arches its back, lowers its pectoral fins and wags its head and tail from side to side in an attempt to scare intruders.
All sharks are dangerous to people.
The three most potentially dangerous sharks are the bull shark, the white shark and the tiger shark. Little of the shark is used by humans.