Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio.
any of a class (Agnatha) of fishes with a cartilaginous skeleton, an eel-like body, and a circular, sucking mouth lacking jaws, consisting of the lampreys and hagfishes
Used by arrangement with John Wiley & Sons, Inc.
nounThe American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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 - Science Definition
The American Heritage® Science Dictionary
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.
Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.