pollock vs Pollachius

pollock and Pollachius both are nouns.

Word	Noun	Adjective	Verb	Adverb
pollock	Yes	No	No	No
Pollachius	Yes	No	No	No

pollock (noun)	Pollachius (noun)
important food and game fish of northern seas (especially the northern Atlantic); related to cod	pollack
lean white flesh of North Atlantic fish; similar to codfish