oyster-fish vs toadfish

oyster-fish and toadfish both are nouns.

Word	Noun	Adjective	Verb	Adverb
oyster-fish	Yes	No	No	No
toadfish	Yes	No	No	No

As nouns, toadfish is a hypernym of oyster-fish; that is, toadfish is a word with a broader meaning than oyster-fish:

oyster-fish: a variety of toadfish
toadfish: bottom-dwelling fish having scaleless slimy skin and a broad thick head with a wide mouth

Other hypernyms of oyster-fish include Opsanus tau.

oyster-fish (noun)	toadfish (noun)
a variety of toadfish	bottom-dwelling fish having scaleless slimy skin and a broad thick head with a wide mouth