archerfish vs percoidean

archerfish and percoidean both are nouns.

Word	Noun	Adjective	Verb	Adverb
archerfish	Yes	No	No	No
percoidean	Yes	No	No	No

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

archerfish: any of several small freshwater fishes that catch insects by squirting water at them and knocking them into the water; found in Indonesia and Australia
percoidean: any of numerous spiny-finned fishes of the order Perciformes

Other hypernyms of archerfish include percoid, percoid fish.

archerfish (noun)	percoidean (noun)
any of several small freshwater fishes that catch insects by squirting water at them and knocking them into the water; found in Indonesia and Australia	any of numerous spiny-finned fishes of the order Perciformes