percoid fish vs percoid

percoid fish and percoid both are nouns.

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

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

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

Other synonyms of percoid fish include percoidean.

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