I offer the hard-shelled northern clam (Mercenaria mercenaria) on the half shell at my bar. The clams are grown in the Great South Bay in New York. The shells are a dull brown with a faint “Indian blanket pattern”. Oyster bars on the west coast sometimes do not offer raw clams, as they are more difficult to open then an oyster. Clams are chewier then oysters because they have a foot for digging into the sand on the bottom of the bay. This is the chewy part in clam chowder.
The terminology around the hard shell clam is confusing. Currently clams are offered by size (count per pound). Eastern clams range in size from the smallest (selects) to littlenecks and top necks (the preferable size for the raw bar) and on to the larger cherrystones. The confusion is that two generations ago there were two names for eastern hard shell clams. The smallest clams were called cherrystones and larger clams were called little necks and top necks. So when a customer asks for cherrystones, I always ask “the small ones?” Larger clams are also called quohogs. This word is derived from the Native American word for clams, poquauhock.
There is also a southern species (Mercenaria campechiensis) of hard shell clams being grown in South Carolina and Florida. The shells have a more pronounced “Indian blanket” color pattern on their shells. Since these clams are all farm raised, they are very small and uniform in size.
The northern hard shell clam
Clams on the half shell
Above is a picture of the northern hard shell clam. The dark color is due to the sediment that the clam was living in.
This is a picture of the southern hard shell clam. Note the difference in color compared to the northern hard shell clam.