genus Pomacanthus vs fish genus

genus Pomacanthus and fish genus both are nouns.

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

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

genus Pomacanthus (noun)	fish genus (noun)
angelfishes	any of various genus of fish