Osteichthyes are a taxonomic grouping of bony fishes.  This group includes ray-finned fishes (class: Actinopterygii) and lobe-finned fishes (class: Sarcopterygii).  This highly diverse group of fishes, which contains almost all fish species, is the most diverse group of vertebrates today. 

The Ocean Sunfish is considered to be the largest member of Osteichthyes, reaching over 2,200 lbs.

 Osteichthyes differ from chondrichthyes by (in most cases) possessing a bony skeleton, a swim bladder, scales (ctenoid, cycloid, or ganoid scales), and external fertilization. (fishionary.fisheries.org/osteichthyes)