dolphinfish vs percoidean

dolphinfish and percoidean both are nouns.

Word	Noun	Adjective	Verb	Adverb
dolphinfish	Yes	No	No	No
percoidean	Yes	No	No	No

As nouns, percoidean is a hypernym of dolphinfish; that is, percoidean is a word with a broader meaning than dolphinfish:

dolphinfish: large slender food and game fish widely distributed in warm seas (especially around Hawaii)
percoidean: any of numerous spiny-finned fishes of the order Perciformes

Other hypernyms of dolphinfish include percoid, percoid fish.

dolphinfish (noun)	percoidean (noun)
large slender food and game fish widely distributed in warm seas (especially around Hawaii)	any of numerous spiny-finned fishes of the order Perciformes
the lean flesh of a saltwater fish found in warm waters (especially in Hawaii)