What are two major groups of bony fish?

The two major groups of bony fish are Actinopterygii, or ray-finned fish, and Sarcopterygii, or lobe-finned fish. Actinopterygii includes the vast majority of fish species, characterized by their fin structures supported by bony rays. Sarcopterygii includes fewer species, such as coelacanths and lungfish, which have fleshy, lobed fins that are more closely related to the limbs of tetrapods. These distinctions highlight the diversity and evolutionary significance of bony fish in aquatic ecosystems.