Some examples of bony fish include the devil firefish, the emperor angelfish, the emperor snapper, the pineapple fish and the garden eel. These bony fish represent only a tiny portion of the 28,000 species of bony fish in the scientific class Osteichthyes, which contains the largest number of living vertebrate species in the world.
Like all fish, bony fish are vertebrates that use gills to breathe and fins for swimming. They also have several distinguishing features, including: a skeleton made of bone, scales, paired fins, paired nostrils, one pair of gill openings and jaws. Over 96 percent of the known species of fish are classified as bony fish. Fish not included in this class are sharks and their relatives, lampreys and hagfishes.
Bony fish are ubiquitous. They inhabit almost every kind of water, including salt water, fresh water and brackish water in shallow ponds and streams. They exist in the ocean at depths of up to 6.8 miles and in lakes as high as 3 miles above sea level. Some bony fish, such as tuna, are pelagic: they only live in the open ocean. Others, such as flatfishes, are bottom dwellers who live on the ocean floor. Gobies bury themselves in the sand at the bottom of the ocean, while sunfish live close to the water's surface. Lungfishes survive drought conditions by burying themselves in the mud at the bottom of ponds. Other bony fish, like the arctic cod, live in sub-freezing waters, surviving temperatures as low as 28 degrees Fahrenheit.