| cyclostome. |
| jawless fish n. Any of several eellike marine and freshwater fishes lacking a jaw and paired appendages that constitute the subphylum Agnatha. The only present-day jawless fish are the hagfish and lampreys. |
jawless fish  (jô'lĭs) Pronunciation Key
Any of various primitive fish of the class Agnatha that lack jaws. Living jawless fish (lampreys and hagfish) have a long, cylindrical body and a cartilaginous skeleton. The numerous extinct species were often heavily armored and are among the earliest vertebrate fossils known. Jawless fish occupy an intermediate evolutionary position between primitive chordates and jawed fish. Also called agnathan. See more at cyclostome. Compare bony fish, cartilaginous fish. |
jawless fish
any of the class Agnatha of primitive, jawless fishes that includes the lampreys and hagfishes (order Cyclostomata), as well as extinct groups
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