sucking fish vs remora

sucking fish and remora both are nouns.

Word	Noun	Adjective	Verb	Adverb
sucking fish	Yes	No	No	No
remora	Yes	No	No	No

As nouns, sucking fish and remora are synonyms defined as:

sucking fish and remora: marine fishes with a flattened elongated body and a sucking disk on the head for attaching to large fish or moving objects

Other synonyms of sucking fish include suckerfish.

sucking fish (noun)	remora (noun)
marine fishes with a flattened elongated body and a sucking disk on the head for attaching to large fish or moving objects	marine fishes with a flattened elongated body and a sucking disk on the head for attaching to large fish or moving objects