Fast Facts About Sharks

Oct. 26, 2007— -- Sharks have seven senses: the five that they share with humans, plus an electrical sense (small pores detect minute electrical currents in the water) and a lateral line (pressure-sensitive cells beneath their skin). The extra senses help them detect prey and avoid predators. (The Shark Almanac The Lyons Press)

A shark does not have a single bone in its body; instead, it has a skeleton made up entirely of cartilage. (Sharks, Skates and Rays: The Biology of Elasmobranch Fishes Johns Hopkins University Press)

There is a lucrative market for shark fins, used in the luxury Asian dish of shark fin soup. Seventy-three million sharks are killed for their fins each year. (Pew Institute for Ocean Science)

Despite substantial commerce in shark fins, meat, liver oil and teeth, restrictions on international trade are in place for only three shark species: basking, whale and white sharks.(Shark Alliance)

Most sharks live for about 25 years, but some of them can live to be a hundred years old. (Buzzle.com)

A shark's teeth are usually replaced every eight days, and some species of sharks shed about 30,000 teeth in their lifetime. (Zoology Laboratory Manual McGraw-Hill)

Sharks do not sleep in the same way as humans do. Even if they seem to be sleeping, they are not, instead they are just resting. (buzzle.com)

As sharks never get cancer, their cartilage is being studied in the hope of developing anti-cancer drugs. (buzzle.com)

Some sharks lay eggs, while most of them give birth to babies. The hammerhead and tiger shark can have as many as 40 babies at one time, while the others can have six to twelve. (buzzle.com)

Most kinds of sharks can swim up to 20-40 miles per hour. The shortfin mako swims up to 68 miles an hour! (Sharks of the World Collins Field Guides)

The size of sharks range from the hand-sized pygmy shark, nine inches in length, to the whale shark, the largest fish, which grows to a length of approximately 39 feet. (buzzle.com)

Great white sharks can grow about 10 inches every year -- they grow to mature lengths of 12 to 14 feet. (buzzle.com)

A shark's brain shows the importance of smell to sharks: up to two-thirds of its brain's total weight is made up of olfactory lobes, which analyze smell. (Shark Alliance)

More than a dozen professional sports teams have taken the name "Sharks." (ReefQuest Center for Shark Research)

Sharks are thought to be solitary hunters, but many species are quite social and travel in schools of up to 100 members. (The Life of Sharks Weidenfeld and Nicolson)

Sharks rarely attack humans unless provoked. The average number of fatalities from shark attacks between 2001 and2006 is 4.3. (National Parks Conservation Association)

Only a few species of sharks attack: three out of 360 species have been involved in a significant number of attacks. (Natal Sharks Board)

In ancient Greece, it was forbidden to eat shark's flesh at women's festivals. (Sharks of the World Collins Field Guides)

Beside "Jaws," sharks have had starring/supporting roles in the movies "Thunderball," "Live and Let Die," "The Spy Who Loved Me" and "Finding Nemo."