Oncorhynchus vs silver salmon

Oncorhynchus and silver salmon both are nouns.

Word	Noun	Adjective	Verb	Adverb
Oncorhynchus	Yes	No	No	No
silver salmon	Yes	No	No	No

Oncorhynchus (noun)	silver salmon (noun)
Pacific salmon including sockeye salmon, chinook salmon, chum salmon, coho salmon	small salmon of northern Pacific coasts and the Great Lakes
	fatty pinkish flesh of small salmon caught in the Pacific and Great Lakes