quahog vs Venus mercenaria

quahog and Venus mercenaria both are nouns.

Word	Noun	Adjective	Verb	Adverb
quahog	Yes	No	No	No
Venus mercenaria	Yes	No	No	No

As nouns, quahog and Venus mercenaria are synonyms defined as:

quahog and Venus mercenaria: an edible American clam; the heavy shells were used as money by some American Indians

Other synonyms of quahog include hard-shell clam, hard clam, Mercenaria mercenaria, quahaug, round clam.

quahog (noun)	Venus mercenaria (noun)
an edible American clam; the heavy shells were used as money by some American Indians	an edible American clam; the heavy shells were used as money by some American Indians
Atlantic coast round clams with hard shells; large clams usually used for chowders or other clam dishes