bottom-dweller vs fish

bottom-dweller and fish both are nouns.

Word	Noun	Adjective	Verb	Adverb
bottom-dweller	Yes	No	No	No
fish	Yes	No	Yes	No

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

bottom-dweller: a fish that lives and feeds on the bottom of a body of water
fish: any of various mostly cold-blooded aquatic vertebrates usually having scales and breathing through gills

bottom-dweller (noun)	fish (noun)
a fish that lives and feeds on the bottom of a body of water	any of various mostly cold-blooded aquatic vertebrates usually having scales and breathing through gills
	the flesh of fish used as food

bottom-dweller (verb)	fish (verb)
	catch or try to catch fish or shellfish
	seek indirectly