jawless fish

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Related to jawless fish: coelacanth, cartilaginous fish

jawless fish

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.

jaw′less fish`

1. Also called cyclostome. any fish of the class Agnatha (and order Cyclostomata), characterized by a circular sucking mouth that lacks jaws.

jaw·less fish

Any of several primitive fish that lack a jaw and resemble the eels. Jawless fish include the lampreys and hagfish. Compare bony fish, cartilaginous fish.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.jawless fish - eel-shaped vertebrate without jaws or paired appendages including the cyclostomes and some extinct formsjawless 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
cephalaspid, osteostracan - extinct jawless fish of the Devonian with armored head
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
hagfish, slime eels, hag - eellike cyclostome having a tongue with horny teeth in a round mouth surrounded by eight tentacles; feeds on dead or trapped fishes by boring into their bodies
References in periodicals archive ?
Over 460 million years ago the first jawless fish swam in shallow seas of what was to become the Appalachian basin of North America.
ROSEBURG - A dam on the North Umpqua River has been modified to make the spawning migration easier for lamprey - a jawless fish that is often mistaken for an eel.
The sea lamprey, river lamprey and brook lamprey ( all kinds of jawless fish ( also find the weir impossible to negotiate as they migrate up stream to spawn.