#108 Shark

Sharks are a group of carnivorous ocean going fish with 368 different species in a total of 30 families. Some species of shark, such as the great white, are infamous among humans because they have been involved in attacks resulting in severe injury and sometimes death. In general, however, sharks are shy fish, who will not attack unless provoked.

Sharks have been around since prehistoric times, with fossils indicating that sharks have maintained their basic shape and evolutionary adaptations for millions of years. The fish is simple, efficient, and relatively intelligent, with evidence suggesting that sharks can acquire skills on par with many land animals. Some sharks are endangered due to heavy human trade in their fins, including many of the large species of shark.

Sharks range in size from the pygmy shark, which is seven inches (18 centimeters) long, to thewhale shark, which can reach 50 feet (15 meters) in length. Most sharks have gray upper bodies and pale lower bodies for camouflage purposes. Sharks have several other characteristics which distinguish them from most fish, beginning with their skeleton, which is formed fromcartilage rather than bone. This makes sharks stronger and more flexible that many fish species.