lancet fish vs malacopterygian

lancet fish and malacopterygian both are nouns.

Word	Noun	Adjective	Verb	Adverb
lancet fish	Yes	No	No	No
malacopterygian	Yes	No	No	No

As nouns, malacopterygian is a hypernym of lancet fish; that is, malacopterygian is a word with a broader meaning than lancet fish:

lancet fish: large elongate scaleless oceanic fishes with sharp teeth and a long dorsal fin that resembles a sail
malacopterygian: any fish of the superorder Malacopterygii

Other hypernyms of lancet fish include soft-finned fish.

lancet fish (noun)	malacopterygian (noun)
large elongate scaleless oceanic fishes with sharp teeth and a long dorsal fin that resembles a sail	any fish of the superorder Malacopterygii