robalo vs snook

robalo and snook both are nouns.

Word	Noun	Adjective	Verb	Adverb
robalo	Yes	No	No	No
snook	Yes	No	No	No

As nouns, snook is a hyponym of robalo; that is, snook is a word with a more specific, narrower meaning than robalo:

robalo: a kind of percoid fish
snook: large tropical American food and game fishes of coastal and brackish waters; resemble pike

robalo (noun)	snook (noun)
a kind of percoid fish	large tropical American food and game fishes of coastal and brackish waters; resemble pike