genus Mobula vs fish genus

genus Mobula and fish genus both are nouns.

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

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

genus Mobula (noun)	fish genus (noun)
type genus of the Mobulidae	any of various genus of fish