Seriphus politus vs croaker

Seriphus politus and croaker both are nouns.

Word	Noun	Adjective	Verb	Adverb
Seriphus politus	Yes	No	No	No
croaker	Yes	No	No	No

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

Seriphus politus: silvery and bluish drumfish of shallow California coastal waters
croaker: any of several fishes that make a croaking noise

Seriphus politus (noun)	croaker (noun)
silvery and bluish drumfish of shallow California coastal waters	any of several fishes that make a croaking noise
	the lean flesh of a saltwater fish caught along Atlantic coast of southern U.S.