Atlantic croaker vs croaker

Atlantic croaker and croaker both are nouns.

Word	Noun	Adjective	Verb	Adverb
Atlantic croaker	Yes	No	No	No
croaker	Yes	No	No	No

As nouns, croaker is a hypernym of Atlantic croaker; that is, croaker is a word with a broader meaning than Atlantic croaker:

Atlantic croaker: a silvery-bodied croaker with dark markings and tiny barbels
croaker: any of several fishes that make a croaking noise

Atlantic croaker (noun)	croaker (noun)
a silvery-bodied croaker with dark markings and tiny barbels	any of several fishes that make a croaking noise
	the lean flesh of a saltwater fish caught along Atlantic coast of southern U.S.