/ˌästēˈikTHē-ēz/
Noun
1. A taxonomic group of fish that have bone, as opposed to cartilaginous, skeletons. The vast majority of fish are osteichthyes, which is an extremely diverse and abundant group consisting of 45 orders, and over 435 families and 28,000 species. It is the largest class of vertebrates in existence today. (wikipedia.org)
2. A class of fish having a skeleton composed of bone in addition to cartilage. (wordnetweb.princeton.edu)
3. Osteichthyes are a taxonomic superclass of fish, also called bony fish that includes the ray-finned fish (Actinopterygii) and lobe finned fish (Sarcopterygii). They are paraphyletic with land vertebrates, in some classification schemes the tetrapods et al are considered to be members of the osteichthyes for this reason.
They are traditionally treated as a class of vertebrates, with subclasses Actinopterygii and Sarcopterygii, but some newer schemes divide them into several separate classes. The vast majority of fish are osteichthyes. Osteichthyes are the most various group of vertebrates, consisting of over 29,000 species, making them the largest class of vertebrates in existence today. (biology-online.org)
Syn: Bony fish