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.
megalodon shark was much bigger than whale shark cause a megalodon shark is almost 100 feet while an whale shark is just 62-75 feet. But the megalodon has been extinct for aboâ¦ut 1.5 million years, leaving the whale shark the biggest shark alive.