damselfish vs percoid fish

damselfish and percoid fish both are nouns.

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

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

Other hypernyms of damselfish include percoid, percoidean.

damselfish (noun)	percoid fish (noun)
small brilliantly colored tropical marine fishes of coral reefs	any of numerous spiny-finned fishes of the order Perciformes