Polyodon vs fish genus

Polyodon and fish genus both are nouns.

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

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

Polyodon (noun)	fish genus (noun)
type genus of the Polyodontidae	any of various genus of fish