References and Further Information: 1  Morrissey, J.F. and J.L. Sumich. 2012. Introduction to the Biology of Marine Life (10th Edition). 2  University of California Museum of Paleontology. Bilateral (left/right) Symmetry.
A lot of things. For one, Whale sharks are fish and use gills to breathe. Blue whales are mammals. The blue whale is also bigger than the whale shark. The tail structure is also different if you watch the whale shark swim, it uses its tail in a side to side motion while the blue whale uses a up and down movement.
Range: All major oceans. Fin, or finback, whales are the second largest animals to ever have lived on earth. In fact, the only animal larger than a finback is a blue whale, which can get up to 100 feet long. Finbacks are a very close second though, reaching up to 80 ft. long, and sometimes a little longer. These whales are dark gray on top from the tip of their mouth to their tail, and are white underneath.