noun, plural: Actinopterygians
Any of a group of Osteichthyes characterized primarily by their lobed fins
Osteichthyes is taxonomic superclass of the phylum Chordata (chordates) and includes groups of fish that have skeletons mainly composed of bone tissues. This superclass includes the ray-finned fish (actinopterygians) and lobe-finned fish (sarcopterygians). The sarcopterygians belongs to the taxonomic class Sarcopterygii, which came from the Greek words sarx (meaning “flesh”) and ptérux (meaning “wing, fins”).
The sarcopterygians are characterized by their fleshy lobed fins as opposed to the actinopterygians that have distinct ray fins. Most bony fish belong to the Actinopterygii. There are only eight living species of lobe-finned fish (Sarcopterygii) including the lungfish and coelacanths. Some species of lobe-finned fish have jointed bones.
Most members of the superclass Osteichthyes are actinopterigians. There are relatively few species of sarcopterygians. This class has only two extant subclasses, Rhipidistia and Actinistia. Rhipdidistia, also referred to as dipnotetrapodomorphs , includes the tetrapods and the lungfish. Actinista contains the coelacanths, such as the West Indian Ocean coelacanth and the king of the sea (Indonesian coelacanth).
- Kingdom: Animalia
- Phylum: Chordata
- Superclass: Osteichthyes
- Class: Sarcopterygii Romer, 1955
- ray-finned fish