Osteichthyes

From WikiMD's Wellness Encyclopedia

Osteichthyes or bony fish (from Greek osteon, bone, and ichthys, fish) are a taxonomic group of fish that includes the ray-finned fish (Actinopterygii) and lobe-finned fish (Sarcopterygii). The group is characterised by having a skeleton primarily composed of bone tissue, as opposed to cartilage. The vast majority of fish are members of Osteichthyes, which is an extremely diverse and abundant group consisting of 45 orders, and over 435 families and 28,000 species.

Characteristics[edit | edit source]

Osteichthyes are characterised by a skeleton made of bone. Their fins contain hard rays or spines because they are stiffened with bone. The remainder of the body is covered in scales which are often covered in a layer of mucus that can help the fish glide through water.

Classification[edit | edit source]

Osteichthyes are divided into two classes, the Actinopterygii, or ray-finned fish, and the Sarcopterygii, or lobe-finned fish. The Actinopterygii include the familiar fish of most fishery catches, such as cod, bass, and tuna. The Sarcopterygii include the coelacanths and lungfishes, although the former are thought to be more closely related to the tetrapods than to the lungfish.

Evolution[edit | edit source]

The earliest known fossil of a bony fish comes from the Upper Silurian of China (c. 423 million years ago), where the Andreolepis and the Guiyu oneiros were found. They are the oldest known bony fish in the world.

See also[edit | edit source]

References[edit | edit source]


External links[edit | edit source]

  • FishBase, a comprehensive database of fish species




Osteichthyes Resources
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