jackknife-fish vs drumfish

jackknife-fish and drumfish both are nouns.

Word	Noun	Adjective	Verb	Adverb
jackknife-fish	Yes	No	No	No
drumfish	Yes	No	No	No

As nouns, drumfish is a hypernym of jackknife-fish; that is, drumfish is a word with a broader meaning than jackknife-fish:

jackknife-fish: black-and-white drumfish with an erect elongated dorsal fin
drumfish: small to medium-sized bottom-dwelling food and game fishes of shallow coastal and fresh waters that make a drumming noise

Other hypernyms of jackknife-fish include drum.

jackknife-fish (noun)	drumfish (noun)
black-and-white drumfish with an erect elongated dorsal fin	small to medium-sized bottom-dwelling food and game fishes of shallow coastal and fresh waters that make a drumming noise