Although shark attacks are rare they are often fatal. Sharks generally attack from the bottom and do not turn over to bite as it is comnonly believed. The fins of sharks are fixed and cannot be opened and closed as the fins of bony fish. The shark does not swim with its dorsal fin above the water as shown in the movies.
Sharks have an excellent sense of smell and is how they are attracted to their prey.
Aside from the great white, hammerhead and tiger sharks are also known to attack humans. Sharks Sharks have a cartilaginous skeleton. Shark attacks are extremely rare but the great white shark shown on the left has a reputation of being the most dangerous.