Pleuronectes vs fish genus

Pleuronectes and fish genus both are nouns.

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

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

Pleuronectes (noun)	fish genus (noun)
type genus of the Pleuronectidae	any of various genus of fish