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.
A whale shark is a shark, the largest living fish in the world,  yet it is a filter feeder.   Even though it doesnt have the same diet as a shark, it is a shark.   â¦ its a shark but is named a whale shark for its large stature and  feeding    It's a shark.