largemouth bass vs largemouth black bass

largemouth bass and largemouth black bass both are nouns.

Word	Noun	Adjective	Verb	Adverb
largemouth bass	Yes	No	No	No
largemouth black bass	Yes	No	No	No

As nouns, largemouth bass and largemouth black bass are synonyms defined as:

largemouth bass and largemouth black bass: a large black bass; the angle of the jaw falls behind the eye

Other synonyms of largemouth bass include largemouth, largemouthed bass, largemouthed black bass, Micropterus salmoides.

largemouth bass (noun)	largemouth black bass (noun)
a large black bass; the angle of the jaw falls behind the eye	a large black bass; the angle of the jaw falls behind the eye
flesh of largemouth bass