The razor clam's distinctive shape gives its name.
The razor clam's distinctive shape gives its name.
Irene H. Stuckey, courtesy of R.I. Natural History Survey

Razor Clam (Ensis directus)

Alternate common names: Straight Razor Clam, Jackknife Clam.
Color: Shell is brownish green.
Size: Up to 10 inches; approximately six times longer than wide.
Habitat: Sandy and muddy bottoms of bays and estuaries, intertidal and subtidal zones.
Seasonal appearance: All year.


Razor clams are narrow, elongate clams named because their long, convex shape resembles an old-fashioned barber's straight-edged razor. The shell tends to be glossy with a purple region near the curving edge. The cream-colored muscular foot protrudes approximately 5 inches from the shell when extended. Like other bivalves, a siphon is present. The hole in the shell from which the syphon protrudes, has a unique keyhole shape.

Life History and Behavior

The razor clam is well adapted for living in soft tidal substrates. Because of its short siphons, it burrows just below the surface to feed. When the tide goes out, it is strong enough to burrow quickly into deeper sand. The foot of the razor clam is larger and more agile than that of other clams. To burrow, the razor clam pushes its narrow foot down deep into the substrate, then expands the foot as an anchor and pulls the body and shell deeper into the sand.

The razor clam is highly sensitive to vibrations and can sense the approach of a nearby predator. Its strong muscular foot enables it to propel itself out of its burrow to escape an attack from below or to burrow quickly if a predator is attacking from above. Clam worms and moon snails prey on razor clams.

Special Notes

Adapted from The Uncommon Guide to Common Life on Narragansett Bay. Save The Bay, 1998.