Rand McNally, 1977. Enchanted Learning Software. There are 354 different species of shark. Sharks are strong animals with very powerful jaws, some of which are capable of killing a human. Sharks vary greatly in size and habitat.
Whale sharks are the largest.
They grow up to 40 feet and weigh up to 15 tons. On the other hand, the smallest shark is 6 inches long and weighs only one ounce. The great difference in length, fin shape and weight results in a great difference in velocity. No firm figures in speed have ever been determined due to this situation. Usually a shark's speed is measured while it swims along with a boat.