Quiz: Remember the definition of mal de mer?
Any of various jawless fish of the order Cyclostomata, having a long, eellike body without scales, a cartilaginous skeleton, and a disklike mouth used for sucking juices from prey. Cyclostomes include the hagfish and lampreys, although some scientists classify these two groups as separate orders.
any member of the order Cyclostomata (class Agnatha), which contains the lamprey and the hagfish (qq.v.). These fish are characterized by a long slender body without scales and fins, a sucking mouth with horny teeth, a cartilaginous skull, and a notochord.