Sciaena aquila vs sciaenid fish

Sciaena aquila and sciaenid fish both are nouns.

Word	Noun	Adjective	Verb	Adverb
Sciaena aquila	Yes	No	No	No
sciaenid fish	Yes	No	No	No

As nouns, sciaenid fish is a hypernym of Sciaena aquila; that is, sciaenid fish is a word with a broader meaning than Sciaena aquila:

Sciaena aquila: large European marine food fish
sciaenid fish: widely distributed family of carnivorous percoid fishes having a large air bladder used to produce sound

Other hypernyms of Sciaena aquila include sciaenid.

Sciaena aquila (noun)	sciaenid fish (noun)
large European marine food fish	widely distributed family of carnivorous percoid fishes having a large air bladder used to produce sound