Merlangus merlangus vs gadoid

Merlangus merlangus and gadoid both are nouns.

Word	Noun	Adjective	Verb	Adverb
Merlangus merlangus	Yes	No	No	No
gadoid	Yes	No	No	No

As nouns, gadoid is a hypernym of Merlangus merlangus; that is, gadoid is a word with a broader meaning than Merlangus merlangus:

Merlangus merlangus: a food fish of the Atlantic waters of Europe resembling the cod; sometimes placed in genus Gadus
gadoid: a soft-finned fish of the family Gadidae

Other hypernyms of Merlangus merlangus include gadoid fish.

Merlangus merlangus (noun)	gadoid (noun)
a food fish of the Atlantic waters of Europe resembling the cod; sometimes placed in genus Gadus	a soft-finned fish of the family Gadidae