stromateid fish vs percoid

stromateid fish and percoid both are nouns.

Word	Noun	Adjective	Verb	Adverb
stromateid fish	Yes	No	No	No
percoid	Yes	No	No	No

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

stromateid fish: small marine fish with a short compressed body and feeble spines
percoid: any of numerous spiny-finned fishes of the order Perciformes

Other hypernyms of stromateid fish include percoid fish, percoidean.

stromateid fish (noun)	percoid (noun)
small marine fish with a short compressed body and feeble spines	any of numerous spiny-finned fishes of the order Perciformes