jawless fish

noun

1. cyclostome.

jawless fish

/ jô′lĭs /

1. 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.
2. Also called agnathan
3. See more at cyclostomeCompare bony fish

Word History and Origins

Origin of jawless fish¹

First recorded in 1965–70; jaw ¹ + -less

Example Sentences

Early jawless fish were likely to have used bony projections surrounding their mouths to modify the mouth's shape while they collected food.

From Science Daily

While most jawless fish have 5-20 gill arches, jawed fish almost never have more than five.

From Science Daily

While McCoy still thinks the Tully Monster was related to jawless fish, she is intrigued by the new study’s findings.

From Scientific American

Lampreys are a jawless fish, older than dinosaurs, that look like their distant relative, the eel, according to the state Department of Fish and Wildlife.

From Seattle Times

They include ancient groups like jawless fish, lineages of early jawed fish called placoderms, ascendant newcomers like cartilaginous and bony fish and the first fishes to hop onto land.

From New York Times