A shark's size depends on the type of shark that it is, as the great white shark can grow as long as 20 feet, while the dwarf lantern shark only grows as long as 6.3 to 6.8 inches. To determine the size of a shark, a researcher first determines the shark's species, and then looks at the data available for that given shark species.
Another one of the smaller sharks is the spined pygmy shark, which grows as long as 6.7 to 7.8 inches. There are many other species of shark that all range between the smallest shark's 10 inches to the great white shark's 20 feet, including the hammerhead shark, the nurse shark, the sand tiger shark, the bull shark and the whale shark. Sharks are powerful creatures and are considered one of the fiercest predators in the ocean.