“Osteichthyes”的概念、定义、翻译、参考文献-科学参考

Osteichthyes

Biology

In traditional classifications the class of vertebrates comprising the ray-finned fishes (subclass Actinopterygii), which comprise the bulk of living marine and freshwater fish species, and the lobe-finned fishes (subclass Sarcopterygii), which comprise the lungfishes (see dipnoi) and coelacanths. All have gills covered with a bony operculum, and a layer of thin overlapping bony scales covers the entire body surface. Bony fish have a swim bladder, which acts as a hydrostatic organ enabling the animal to remain suspended in the water at any depth. In the lungfishes this bladder acts as a lung. This traditional class is paraphyletic because it excludes amphibians, reptiles, and mammals, which all share a common ancestor with the bony fishes. Hence, Osteichthyes is now applied to the clade containing the bony fishes and their tetrapod relatives. See also dipnoi; teleostei. Compare chondrichthyes.

Geology and Earth Sciences

Superclass of fish in which the internal skeleton is largely ossified, and which also have teeth, plates, or scales of dermal bone. Characteristic features are: the terminal mouth; homocercal tail; operculum covering the gills; usually many flat, bony scales embedded in the skin, with epidermis over them; and the presence of a swim bladder (although sometimes this has been lost in the course of later evolution). With about 28 000 species it is the largest class of vertebrate animals. The Osteichthyes have a fossil history going back to the Lower Devonian; they include the Crossopterygii, the Dipnoi, the Chondrostei, the Holostei, and the Teleostei.

单词	Osteichthyes
释义	Osteichthyes Biology In traditional classifications the class of vertebrates comprising the ray-finned fishes (subclass Actinopterygii), which comprise the bulk of living marine and freshwater fish species, and the lobe-finned fishes (subclass Sarcopterygii), which comprise the lungfishes (see dipnoi) and coelacanths. All have gills covered with a bony operculum, and a layer of thin overlapping bony scales covers the entire body surface. Bony fish have a swim bladder, which acts as a hydrostatic organ enabling the animal to remain suspended in the water at any depth. In the lungfishes this bladder acts as a lung. This traditional class is paraphyletic because it excludes amphibians, reptiles, and mammals, which all share a common ancestor with the bony fishes. Hence, Osteichthyes is now applied to the clade containing the bony fishes and their tetrapod relatives. See also dipnoi; teleostei. Compare chondrichthyes. Geology and Earth Sciences Superclass of fish in which the internal skeleton is largely ossified, and which also have teeth, plates, or scales of dermal bone. Characteristic features are: the terminal mouth; homocercal tail; operculum covering the gills; usually many flat, bony scales embedded in the skin, with epidermis over them; and the presence of a swim bladder (although sometimes this has been lost in the course of later evolution). With about 28 000 species it is the largest class of vertebrate animals. The Osteichthyes have a fossil history going back to the Lower Devonian; they include the Crossopterygii, the Dipnoi, the Chondrostei, the Holostei, and the Teleostei.
随便看	electronic brakeforce distribution electronic brokerage electronic business electronic cheque electronic commerce electronic commerce agent electronic data interchange electronic data processing electronic device electronic discovery electronic effects electronic efficiency electronic filing Electronic Frontier Foundation electronic funds transfer at point of sale electronic funds transfer system electronic goods electronic graffiti electronic image stabilization electronic imaging electronic ink electronic journal electronic learning electronic library electronic lock