Sharks

Bouyancy/Skeletal Structure

Unlike most fish that have a buoyancy bladder that can inflate and deflate to rise and sink, the sharks have a huge oily liver that helps them float as well as with the help of the light cartilage skeletal structure. This is important to them because of the way their body moves. If they had a normal gas bladder, it would be crushed with every full-body bend. A bony skeletal structure would not do because of the way they move. The lighter cartilage allows them to have quicker reaction time, easier movement, and bend their body farther for a faster turn. This is a result of the amazing durability and flexibility of cartilage.

Although mainly composed of cartilage, their unique skeleton does have a few bones deposited around their head for extra protection. The lighter cartilage skeleton allows them more speed, creating less drag and less weight. With these seemingly obscure parts, and oddly crafted skeleton, the shark is more versatile than ever, deadly and unstoppable.