percoid fish vs percoidean

percoid fish and percoidean both are nouns.

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

As nouns, percoid fish and percoidean are synonyms defined as:

percoid fish and percoidean: any of numerous spiny-finned fishes of the order Perciformes

Other synonyms of percoid fish include percoid.

percoid fish (noun)	percoidean (noun)
any of numerous spiny-finned fishes of the order Perciformes	any of numerous spiny-finned fishes of the order Perciformes