black rudderfish vs stromateid

black rudderfish and stromateid both are nouns.

Word	Noun	Adjective	Verb	Adverb
black rudderfish	Yes	No	No	No
stromateid	Yes	No	No	No

As nouns, stromateid is a hypernym of black rudderfish; that is, stromateid is a word with a broader meaning than black rudderfish:

black rudderfish: blackish fish of New England waters
stromateid: small marine fish with a short compressed body and feeble spines

Other hypernyms of black rudderfish include butterfish, stromateid fish.

black rudderfish (noun)	stromateid (noun)
blackish fish of New England waters	small marine fish with a short compressed body and feeble spines