They are found in tropical, temperate, and polar seas.
Bony fishes exist in fresh water, seawater, and brackish environments.
This - Body shape reduces drag and requires a minimum amount of energy to swim. The venous side of the heart is preceded by an enlarged chamber called the sinus venosus. The arterial side of the heart is followed by a thickened muscular cavity called the bulbus arteriosus - Oxygenated blood flows from the gill filaments to the organs of the head and body. A complex system of arteries, veins, and capillaries circulates blood through the body. The esophagus in bony fishes is short and expandable so that large objects can be swallowed.