white perch vs serranid fish

white perch and serranid fish both are nouns.

Word	Noun	Adjective	Verb	Adverb
white perch	Yes	No	No	No
serranid fish	Yes	No	No	No

As nouns, serranid fish is a hypernym of white perch; that is, serranid fish is a word with a broader meaning than white perch:

white perch: small silvery food and game fish of eastern United States streams
serranid fish: marine food sport fishes mainly of warm coastal waters

Other hypernyms of white perch include serranid.

white perch (noun)	serranid fish (noun)
small silvery food and game fish of eastern United States streams	marine food sport fishes mainly of warm coastal waters