Living species range from the primitive lampreys and hagfishes through the cartilaginous sharks, skates, and rays to the abundant and diverse bony fishes. Species range in length from 0.4 …
The freshwater habitats may be seen to be of many kinds. Fishes found in mountain torrents, Arctic lakes, tropical lakes, temperate streams, and tropical rivers will all differ from each …
The swim bladder of fishes follows the same developmental pattern as the lungs of land vertebrates. There is no doubt that the two structures have the same historical origin in …
Ray, any of the cartilaginous fishes of the order Batoidei, related to sharks and placed with them in the class Chondrichthyes. Rays are distinguished from sharks by a flattened, …
Two pairs of fins correspond to arms (pectoral fins) and legs (pelvic, or ventral, fins). There are also several unpaired, or median, fins—dorsal (back), caudal (tail), and anal (belly). Fish …
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