― The whale shark holds the title of the world's biggest shark species. Growing to a length of about 65 feet (the length of about 1 1/2 school buses!) and weighing about 75,000 pounds, this streamlined fish is really a gentle giant. ∙ Some areas frequented by these sharks, such as Ningaloo Reef, Australia, have become popular tourist destinations because of their swim-with-sharks programs. ∙ The second-biggest shark species is the basking shark, which grows to about 40 feet. .