The next class is Osteichthyes or bony fishes. These fishes have endoskeletons made of bone as well as .jaws and paired appendages. Their gill arches are internal to gills and are covered by a bony operculum. The majority do have a swim bladder. Osteichthyes appeared during the Devonian period and have been the dominent vertebrates since. They started in freshwater and moved into salt water.
Salmon (Salmo Salar)
Diversity of vertebrates. (2010). Retrieved from http://www.shsu.edu/~bio_mlt/Chapter3.html
