dolphinfish vs percoid fish

dolphinfish and percoid fish both are nouns.

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

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

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

Other hypernyms of dolphinfish include percoid, percoidean.

dolphinfish (noun)	percoid fish (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)