bony fish

any fish of the class Osteichthyes, characterized by gill covers, an air bladder, and a skeleton composed of bone in addition to cartilage.

[1805-15, Amer.]

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Any member of the vertebrate class Osteichthyes, including the great majority of living fishes and all the world's sport and commercial fishes.

Also called Pisces, the class excludes jawless fishes (hagfishes and lampreys) and cartilaginous fishes (sharks, skates, and rays). There are more than 20,000 species worldwide, all with a skeleton at least partly composed of true bone. Other features include, in most species, a swim bladder (an air-filled sac to give buoyancy), gill covers over the gill chamber, bony platelike scales, a skull with sutures, and external fertilization of eggs. Bony fishes occur in all freshwater and ocean environments.

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▪ class of fish

      any member of the superclass Osteichthyes, a group made up of the classes Sarcopterygii (lobe-finned fishes) and Actinopterygii (ray-finned fishes) in the subphylum Vertebrata, including the great majority of living fishes and virtually all the world's sport and commercial fishes. The scientific term Pisces has also been used to identify this group of fishes. Osteichthyes excludes the jawless fishes of the class Agnatha (hagfishes and lampreys) and the cartilaginous fishes constituting the class Chondrichthyes (sharks, skates, and rays) but includes the 20,000 species and more than 400 families of modern bony fishes (infraclass Teleostei) of the world, as well as a few primitive forms. The primary characteristic of bony fishes is a skeleton at least partly composed of true bone (as opposed to cartilage). Other features include, in most forms, the presence of a swim bladder (an air-filled sac to give buoyancy), gill covers over the gill chamber, bony platelike scales, a skull with sutures, and external fertilization of eggs.

 Bony fishes occur in all freshwater and ocean environments, including caves, deep-sea habitats, and thermal springs and vents. The variety of shapes and behavioral habits is remarkable. Their body sizes range from tiny species such as the pygmy goby (Pandaka pygmaea; 12 mm [0.5 inch]) to the enormous marlins (marlin) and swordfishes (swordfish) (family Istiophoridae) with lengths up to 4.5 m (15 feet) and the ocean sunfish ( mola mola; see photograph—>), which may weigh over 900 kg (1 ton).

 

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