Clams

Mercenaria mercenaria

About This Animal

SIZE: Variable depending on species and location

RANGE: Clams are found worldwide

HABITAT: Squid eggs are attached to rocks and small boulders or aquatic vegetation on sandy or muddy bottoms. Larvae are found in surface waters. Juveniles also live in the upper water column in water 165 to 1,650 feet deep. Adults live over mud or sand/mud substrates of the continental shelf and upper continental slope in waters up to 1,300 feet deep.

DIET: Filter feed plankton out of the water column

ON EXHIBIT: The Lobster tank in Boneless Beauties in Ocean Journey

While we think of clams as stationary shelled animals, they start life as larvae floating in the water column.  When they settle, they will anchor themselves to the ocean bottom with a protein fiber called byssal threads. Clams are filter feeders, eating microscopic algae in the water.  Absences of clams in areas where they should occur can lead to an increase in algal blooms.  One type of clam, the ocean quahog, is one of the longest-lived animals in the world: they can live up to 200 years!  When it comes to seafood, there are many species of clam that are used and most are a sustainable choice.  Common species farmed or fished include:

1. Ocean Quahog or Hard Clam (Arctica islandica)

2. Atlantic Surfclam (Spisula solidissima)

3. Cherrystones or Littlenecks (Mercenaria mercenaria)

Clams are not considered threatened.  In the U.S., clam populations drastically decreased in the 1980s.  However, thanks to development in aquaculture and restoration programs, they are still a staple in the seafood market. Clam farms help improve water quality as the animals filter-feed, removing algae and other particles from the water.  When they are fished from the wild, they are harvested with dredges that burrow into the substrate and remove the clam from its anchor.