genus Gerres vs fish genus

genus Gerres and fish genus both are nouns.

Word	Noun	Adjective	Verb	Adverb
genus Gerres	Yes	No	No	No
fish genus	Yes	No	No	No

As nouns, fish genus is a hypernym of genus Gerres; that is, fish genus is a word with a broader meaning than genus Gerres:

genus Gerres (noun)	fish genus (noun)
type genus of the Gerreidae	any of various genus of fish