Tetragonurus vs fish genus

Tetragonurus and fish genus both are nouns.

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

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

Tetragonurus (noun)	fish genus (noun)
a genus of Stromateidae	any of various genus of fish