haddock vs Melanogrammus aeglefinus

haddock and Melanogrammus aeglefinus both are nouns.

Word	Noun	Adjective	Verb	Adverb
haddock	Yes	No	No	No
Melanogrammus aeglefinus	Yes	No	No	No

As nouns, haddock and Melanogrammus aeglefinus are synonyms defined as:

haddock and Melanogrammus aeglefinus: important food fish on both sides of the Atlantic; related to cod but usually smaller

haddock (noun)	Melanogrammus aeglefinus (noun)
important food fish on both sides of the Atlantic; related to cod but usually smaller	important food fish on both sides of the Atlantic; related to cod but usually smaller
lean white flesh of fish similar to but smaller than cod; usually baked or poached or as fillets sauteed or fried