Priacanthus arenatus vs percoid

Priacanthus arenatus and percoid both are nouns.

Word	Noun	Adjective	Verb	Adverb
Priacanthus arenatus	Yes	No	No	No
percoid	Yes	No	No	No

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

Priacanthus arenatus: brightly colored carnivorous fish of western Atlantic and West Indies waters
percoid: any of numerous spiny-finned fishes of the order Perciformes

Other hypernyms of Priacanthus arenatus include percoid fish, percoidean.

Priacanthus arenatus (noun)	percoid (noun)
brightly colored carnivorous fish of western Atlantic and West Indies waters	any of numerous spiny-finned fishes of the order Perciformes