sand stargazer vs percoid fish

sand stargazer and percoid fish both are nouns.

Word	Noun	Adjective	Verb	Adverb
sand stargazer	Yes	No	No	No
percoid fish	Yes	No	No	No

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

sand stargazer: small pallid fishes of shoal tropical waters of North America and South America having eyes on stalks atop head; they burrow in sand to await prey
percoid fish: any of numerous spiny-finned fishes of the order Perciformes

Other hypernyms of sand stargazer include percoid, percoidean.

sand stargazer (noun)	percoid fish (noun)
small pallid fishes of shoal tropical waters of North America and South America having eyes on stalks atop head; they burrow in sand to await prey	any of numerous spiny-finned fishes of the order Perciformes