Hexagrammos vs fish genus

Hexagrammos and fish genus both are nouns.

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

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

Hexagrammos (noun)	fish genus (noun)
type genus of the Hexagrammidae	any of various genus of fish