Pomacentrus vs fish genus

Pomacentrus and fish genus both are nouns.

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

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

Pomacentrus (noun)	fish genus (noun)
type genus of the Pomacentridae: damselfishes	any of various genus of fish