harvestfish vs butterfish

harvestfish and butterfish both are nouns.

Word	Noun	Adjective	Verb	Adverb
harvestfish	Yes	No	No	No
butterfish	Yes	No	No	No

As nouns, butterfish is a hypernym of harvestfish; that is, butterfish is a word with a broader meaning than harvestfish:

harvestfish: butterfish up to a foot long of Atlantic waters from Chesapeake Bay to Argentina
butterfish: small marine fish with a short compressed body and feeble spines

Other hypernyms of harvestfish include stromateid, stromateid fish.

harvestfish (noun)	butterfish (noun)
butterfish up to a foot long of Atlantic waters from Chesapeake Bay to Argentina	small marine fish with a short compressed body and feeble spines
	slippery scaleless food fish of the northern Atlantic coastal waters
	any of numerous small flat Atlantic food fish having smooth skin