what are fish with calcified skeletons called?
They are called bony fish because their skeletons are calcified, making them much harder than the cartilage bones of the chondrichthyes. The bony fishes have great maneuverability and speed, highly specialized mouths equipped with protrusible jaws, and a swim bladder to control buoyancy.ISH-how fish swim. The density of water makes it very difficult to move in, but fish can move very smoothly and quickly. A swimming fish is relying on its skeleton for framework, its muscles for power, and its fins for thrust and direction. The skeleton of a fish is the most complex in all vertebrates.