9. Ocean Sunfish | Total length 10.82 feet (3.3 meters)
Also known as a mola mola, the wonderfully weird ocean sunfish is the heaviest of all bony fish. Affectionately called a "swimming head," the giant fish without a tail has been measured at 10.82 feet and an astonishing 5070 pounds. And if you're wondering how a fish without a tail swims, it powers itself by its mighty fins.