genus Fistularia vs fish genus

genus Fistularia and fish genus both are nouns.

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

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

genus Fistularia (noun)	fish genus (noun)
type genus of the family Fistulariidae	any of various genus of fish