remora vs whalesucker

remora and whalesucker both are nouns.

Word	Noun	Adjective	Verb	Adverb
remora	Yes	No	No	No
whalesucker	Yes	No	No	No

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

remora: marine fishes with a flattened elongated body and a sucking disk on the head for attaching to large fish or moving objects
whalesucker: large blue Pacific remora that attaches to whales and dolphins

Other hyponyms of remora include Echeneis naucrates, sharksucker, Remilegia australis, whale sucker.

remora (noun)	whalesucker (noun)
marine fishes with a flattened elongated body and a sucking disk on the head for attaching to large fish or moving objects	large blue Pacific remora that attaches to whales and dolphins