surf fish vs percoid

surf fish and percoid both are nouns.

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

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

surf fish: small to medium-sized shallow-water fishes of the Pacific coast of North America
percoid: any of numerous spiny-finned fishes of the order Perciformes

Other hypernyms of surf fish include percoid fish, percoidean.

surf fish (noun)	percoid (noun)
small to medium-sized shallow-water fishes of the Pacific coast of North America	any of numerous spiny-finned fishes of the order Perciformes
a fish of the Pacific coast of North America