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Any of various elongated marine and freshwater fishes lacking jaws and paired appendages, sometimes thought to constitute the taxon Agnatha. The only extant jawless fishes are the hagfishes and the lampreys.
1. Also called cyclostome. any fish of the class Agnatha (and order Cyclostomata), characterized by a circular sucking mouth that lacks jaws.
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|Noun||1.||jawless fish - eel-shaped vertebrate without jaws or paired appendages including the cyclostomes and some extinct forms|
aquatic vertebrate - animal living wholly or chiefly in or on water
Agnatha, superclass Agnatha - superclass of eel-shaped chordates lacking jaws and pelvic fins: lampreys; hagfishes; some extinct forms
ostracoderm - extinct fish-like jawless vertebrate having a heavily armored body; of the Paleozoic
heterostracan - extinct jawless fish with the anterior part of the body covered with bony plates; of the Silurian and Devonian
anaspid - extinct small freshwater jawless fish usually having a heterocercal tail and an armored head; of the Silurian and Devonian
conodont - small (2 inches long) extinct eellike fish with a finned tail and a notochord and having cone-shaped teeth containing cellular bone; late Cambrian to late Triassic; possible predecessor of the cyclostomes
cyclostome - primitive aquatic vertebrate
lamper eel, lamprey, lamprey eel - primitive eellike freshwater or anadromous cyclostome having round sucking mouth with a rasping tongue