clupeid fish vs clupeid

clupeid fish and clupeid both are nouns.

Word	Noun	Adjective	Verb	Adverb
clupeid fish	Yes	No	No	No
clupeid	Yes	No	No	No

As nouns, clupeid fish and clupeid are synonyms defined as:

clupeid fish and clupeid: any of numerous soft-finned schooling food fishes of shallow waters of northern seas

clupeid fish (noun)	clupeid (noun)
any of numerous soft-finned schooling food fishes of shallow waters of northern seas	any of numerous soft-finned schooling food fishes of shallow waters of northern seas