Quahog clams are known by many names, but their scientific name is a reference to their use as a form of currency in Native American populations.

Mercenaria Mercenaria, commonly known as Quahog, has many names, such as Hard clam, Hard-shell, and Round clam. Native to the eastern coastlines of North America and Central America, the Quahog is a delectable saltwater bivalve mollusk. It is also an important commercial species that are highly coveted for a said appeal to the human palette. Because of its storied record of being traded, the Quahog’s scientific name, “Mercenaria,” is derived from the Latin word for commerce.

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Quahogs can reach a size of 3 inches and have a somewhat robust shell with asymmetrical, raised hinges on the anterior. While the inside is often white with noticeable purple spots, the outside is typically dingy white or grayish. The size and shape of the two separate halves are roughly equal and sub-ovate or triangular. 

Typical Quahog with its notable grooves being held for scale
Typical Quahog with its notable grooves being held for scale

Credit: Travis S.

Quahogs’ outermost fold secretes aragonite on a constant basis, increasing the shell’s thickness and providing it with several circumferential lines. On the edge of the shell, Quahogs have 3 well-developed teeth that help to tighten the shell when it is closed. Its siphons are used by it for breathing and sustenance acquisition.


Because Quahogs are suspending feeders, they ingest plankton, a type of small animal and vegetation that is brought in by the sea. The siphons of the Quahog stick upwards and through, encircling sludge when it conceals itself behind a bed of sand and dirt. Water is drained over the gills of the Quahog using the inhalant siphon. 

A mucosal film that envelopes the gills traps any food debris while millions of minute cilia, which resemble tiny hairs, propel the water across the gills. A pair of muscles known as the palps push the food-mucous combination into the mouth of the Quahog after traveling down a channel just above the foot.


Quahogs have a natural distribution anywhere along the east coast of America, from the Gulf of St. Lawrence towards the Gulf of Mexico, where they can be found living in coastal waters at depths of up to 32 ft. They are most frequently seen in abundance on mud flats and sand flats in intertidal zones. 

A bucket filled with Quahogs notable for their shell color
A bucket filled with Quahogs notable for their shell color

Credit: NOAA Restoration Center, Tom, and Louise Kane

Quahog requires tides to consume food, respiration, and waste disposal, but, the choppy seas found in the surf zone could wash them away. Because they provide the ideal salt and temperatures for survival, the clam’s specified regions that the Quahog frequents are suitable habitats.


Male Quahogs release sperm into the ocean to breed, which prompts the female to deposit eggs. Spawning starts whenever the water temperature reaches 73°F and other environmental indicators, such as a pH change, occur. Trochophore larvae develop from fertilized eggs over the course of the first 12 to 14 hours. 

They have microscopic cilia that enable them to float around while they are in this form, which is tubular. The newly formed foot secretes byssal threads, which the larvae use to attach themselves to rocks, seaweed, or other sedimentary deposits, which is available after they have shed their lobes. Then, its shell will exude, starting to calcify. Only 10% of all veliger larvae mature into fully-fledged Quahog.


Quahog is scattered by currents when they are in their free-floating phase. Other creatures, including crabs, prey on Quahog. The biggest threats to Quahog are human beings, changes in the ocean ecosystem caused by climate change, and pollution.

A cluster of Quahogs caught in South Carolina
A cluster of Quahogs caught in South Carolina

Credit: NOAA Restoration Center

Quahogs are highly sensitive to changes in pH, temperature, and salt concentration, with the smallest changes causing the most declines in a given population. The fact that their flesh is edible and highly coveted has made the farming of Quahog into millions of dollar commercial fish industry.

Facts about the Quahog

  1. Quahogs have a lifespan of up to a century.
  2. By examining the grooves on the exterior of the shell, you can determine a Quahog’s age.
  3. Quahog is also known as a hard shell clam.
  4. Quahogs can hop around on one foot.
  5. As filter feeders, Quahogs contribute to the ocean’s ecosystem.


How old is the oldest Quahog clam?

Also known as “Ming the clam,” was determined to be 507 years old, breaking the Guinness World Record. This Quahog was discovered off the coast of Iceland in 2006. At first, it was estimated at about 405 years, which was still a world record. However, the figure increased to 507 years old in 2013 when scientists looked again at the shell using better methods of determining.

Can Quahogs make pearls?

Quahogs may form pearls that resemble non-nacreous ceramics, and their shells often have an irregular internal coloration of white and violet. Quahog pearls may be found in a range of hues, from light to dark and from a light shade of rosy lavender to a deep shade of purple.

Why is it called a Quahog?

The Narragansett American Indians invented the word Quahog, which is an acronym for “poquauhock.” Due to the usage of these shells to create beads that were, in turn, used as money, the quahog is generally understood as Mercenaria mercenaria, the Latin word for money or commerce.

Do Quahog clams have eyes?

While some species of mollusks and clams have appendages that can be comparable to eyes, Quahogs don’t possess such sensory ability. However, that doesn’t mean that they have no sense of the external world. Quahogs have acute tactile responses and are able to feel slight shifts in water vibration alongside chemical signatures.

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