ribbonfish vs king of the herring

ribbonfish and king of the herring both are nouns.

Word	Noun	Adjective	Verb	Adverb
ribbonfish	Yes	No	No	No
king of the herring	Yes	No	No	No

As nouns, ribbonfish and king of the herring are synonyms defined as:

ribbonfish and king of the herring: thin deep-water tropical fish 20 to 30 feet long having a red dorsal fin

Other synonyms of ribbonfish include oarfish, Regalecus glesne.

ribbonfish (noun)	king of the herring (noun)
marine fish having a long compressed ribbonlike body	thin deep-water tropical fish 20 to 30 feet long having a red dorsal fin
thin deep-water tropical fish 20 to 30 feet long having a red dorsal fin