sciaenid fish vs percoidean

sciaenid fish and percoidean both are nouns.

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

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

sciaenid fish: widely distributed family of carnivorous percoid fishes having a large air bladder used to produce sound
percoidean: any of numerous spiny-finned fishes of the order Perciformes

Other hypernyms of sciaenid fish include percoid, percoid fish.

sciaenid fish (noun)	percoidean (noun)
widely distributed family of carnivorous percoid fishes having a large air bladder used to produce sound	any of numerous spiny-finned fishes of the order Perciformes