threadfin vs percoid fish

threadfin and percoid fish both are nouns.

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

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

threadfin: mullet-like tropical marine fishes having pectoral fins with long threadlike rays
percoid fish: any of numerous spiny-finned fishes of the order Perciformes

Other hypernyms of threadfin include percoid, percoidean.

threadfin (noun)	percoid fish (noun)
mullet-like tropical marine fishes having pectoral fins with long threadlike rays	any of numerous spiny-finned fishes of the order Perciformes