genus Oxylebius vs fish genus

genus Oxylebius and fish genus both are nouns.

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

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

genus Oxylebius (noun)	fish genus (noun)
a genus of Hexagrammidae	any of various genus of fish