wolffish vs soft-finned fish

wolffish and soft-finned fish both are nouns.

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

As nouns, soft-finned fish is a hypernym of wolffish; that is, soft-finned fish is a word with a broader meaning than wolffish:

wolffish: 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 wolffish include malacopterygian.

wolffish (noun)	soft-finned fish (noun)
large ferocious northern deep-sea food fishes with strong teeth and no pelvic fins	any fish of the superorder Malacopterygii
large elongate scaleless oceanic fishes with sharp teeth and a long dorsal fin that resembles a sail