lancet fish vs soft-finned fish

lancet fish and soft-finned fish both are nouns.

Word	Noun	Adjective	Verb	Adverb
lancet fish	Yes	No	No	No
soft-finned fish	Yes	No	No	No

As nouns, soft-finned fish is a hypernym of lancet fish; that is, soft-finned fish 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
soft-finned fish: any fish of the superorder Malacopterygii

Other hypernyms of lancet fish include malacopterygian.

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