Sharks are fish, but unlike other fish, their skeletons are made of cartilage rather than bone, and instead of smooth, flat scales they have sharp, tooth-like scales called denticles. Scientists believe that sharks are 2... More »

www.reference.com Pets & Animals Marine Life Sharks

The bull shark is one of the few shark species that live both in salt water and freshwater. These sharks can travel far up rivers, swimming as far as 2.220 miles up the Amazon River in Peru and over 1.800 miles up the Mi... More »

www.reference.com Pets & Animals Marine Life Sharks

The megalodon shark grew to be between 45 and 60 feet long and scientists believe it was the largest prehistoric shark to have ever lived. The name "megalodon" means "big tooth" and its teeth grew to be around 7 inches l... More »

www.reference.com Pets & Animals Marine Life Sharks

Sharks belong to the fish family, and are characterized by having skeletons that are made from cartilage rather than bone, a series of five to seven gill slits located on both sides of their body for respiration purposes... More »

An amazing fact about sharks is that the skins of females are much thicker than that of males. This is because male sharks tend to bite the females during mating. In its lifetime, a shark can go through about 30,000 teet... More »

www.reference.com Pets & Animals Marine Life Sharks

Blue sharks are known for their distinct coloring, which allows them to blend in with ocean water. From above, the water appears darker and camouflages the shark's dark blue back, while its white underside resembles the ... More »

www.reference.com Pets & Animals Marine Life Sharks

Cookiecutter sharks, also known as cigar sharks, are unusual, small predators that commonly attack much larger prey. Their upper and lower teeth are quite different, with the hook-like upper teeth being much smaller than... More »

www.reference.com Pets & Animals Marine Life Sharks