dolphinfish vs percoid

dolphinfish and percoid both are nouns.

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

As nouns, percoid is a hypernym of dolphinfish; that is, percoid 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: any of numerous spiny-finned fishes of the order Perciformes

Other hypernyms of dolphinfish include percoid fish, percoidean.

dolphinfish (noun)	percoid (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)