Until the late 16th century sharks were called Sea-dogs. The name shark first came into use around the late 1560s to refer to the large Sharks of the Carribean Sea, and later to Sharks in general. The name Shark is derived from the Mayan word for shark pronounced shock or shawk.

Sharks never run out of teeth. If one is lost, another spins forward from the rows and rows of backup teeth. A shark may grow and use over 20,000 teeth in its lifetime!

Sharks can smell a drop of blood even ¼ mile away from it and its sense of vibrations is even acute. A little bit of splashing in water can invite the shark to join the group.

Baby sharks are called pups and sharks can have from 1 to 100 babies at a time, depending on the type of shark.

A shark if inverted enters a natural state of paralysis. This state is called 'tonic' and the shark usually becomes dull and unresponsive for a while. Researchers use this condition for handling sharks safely. The condition is termed tonic immobility.

The shark has the greatest electricity sensitivity known in all animals. This sense is used to find prey hidden in sand in bottom feeding sharks, by detecting the nerve impulses. It is this sense that sometimes confuses a shark into attacking a boat, when the metal interacts with the salt water.

Some sharks must swim constantly to "breathe" oxygen from water passing through their gills. Other species can achieve this while stationary.

Sharks do not sleep. Rather, they experience alternating periods of activity and rest.

Sharks are diverse reproducers, and their mating has been observed only on rare occasions. Some species are egg-laying (oviparous), while others bear live young (viviparous). Adult sharks do not care for their newborn pups, which are born or hatched as smaller, juvenile versions of their parents.

Sharks have skeletons that are made of cartilage.

A remora is a kind of fish that hitches a ride on the back of the shark.

Tiger sharks are the only ones on this earth to practice cannibalism before birth.

A shark is neither fish nor a mammal. It is something in between having some traits of both.

Sharks are considered to be prehistoric animals.

Shark bite can leave you bleeding profusely underwater, but you won't know it until you see the blood-most shark bites are painless.

Young men in the Polynesian Islands used to prove their manhood by wrestling sharks in shallow lagoons. The victor pulled the shark ashore, slice of a fin and present it to his favorite girl.

Many sharks need to keep moving or drown. So their specimens anesthetized for shipment to aquariums had to be "walked" around by men in their tanks while carefully looking for signs that they are about to wake up.

Sharks seem to have a life without pains. They have been stabbed, hacked up, fatally wounded, but have been seen eating their own entrails. They would even attack back to drown the boat. It dies very slowly from tail to head-secret unknown

A truly effective shark repellent has been found in the glands of harmless-looking Flounder called "Moses Sole". No fish can eat it as one drop of its milky poison paralyzes the predator, however nothing beats humans! Israeli fishermen eat it regularly!

The carpet shark looks like cactus of the ocean. It lies motionless in the bottom of the sea until small animals in search of food "attempt to nibble on its leaf like projections!"