Photography by Lori M. Nichols

Knobbed whelk

Busycon carica

The knobbed whelk is the official state shell of New Jersey.

Knobs — some more pronounced than others — form around the spire, giving it its name.

Size: 100-240 mm; common, although uncommon to find whole, unbroken shells.

Channeled whelk

Busycotypus canaliculatus

The channeled whelk has a pear-shaped shell with raised spires. Less damaged shells show "beads" lining the spires.

Size: 100-215 mm; common, although uncommon to find whole, unbroken shells.

Common slipper shell or oyster-pest

Crepidula fornicata

The common slipper shell gets its name from its appearance: it looks like a slipper.

These animals are often found in chains of up to 12, attached to mussels or oysters. They start out as males and turn into females as they grow larger.

Size: 20-50 mm; very common.

Eastern white slippersnail

Crepidula plana

The eastern white slippersnail has a convex, or sometimes flat, shell due to where the animal lives: inside the shells of snails and slugs, feeding off the waste from the hermit crabs often living inside the shell as well.

Size: 12-30 mm; very common.

Blood ark

Lunarca ovalis

The blood ark has a somewhat circular shell with visible ribs (those lines extending from the top to bottom).

It gets its name from having red blood, noting the presence of hemoglobin, which makes it unlike most mollusks.

Size: 25-75 mm; very common.

Transverse ark

Anadara transversa

The transverse ark has a white shell (it may be stained a darker color) with ribs radiating from the top.

Size: 13-38 mm; common.

Ponderous ark

Noetia ponderosa

The ponderous ark has a shell with a high arch and squared-off, trapezoid-like shape. From the side, it almost looks like a wave crashing along the shoreline. It's heavy for its size.

The photo in the upper right shows its teeth.

Size: up to 60 mm; common, but usually as a fossil in New Jersey.

Blue mussel

Mytilus edulis

The outside of the blue mussel shell is dark blue or black in color; the inside is often a shimmery white with dark purple borders.

Both halves of this bivalve are often found intact on beaches near inlets.

Size: 40-105 mm; very common.

Ribbed mussel

Geukensia demissa

The ribbed mussel has a somewhat thin, but strong, fan-shaped shell with noticeable ribs.

The inside of the shell is pearly gray.

Size: 60-100 mm; very common.

Cayenne keyhole limpet

Diodora cayenensis

The Cayenne keyhole limpet is shaped like a cone, with a small hole at the top, called the keyhole.

This limpet lives in inlets and offshore waters and is occasionally found washed up on ocean beaches.

Size: 15-50 mm; common.

Atlantic surf-clam

Spisula solidissima

One of the most commonly found shells on New Jersey beaches, and easily recognizable by its large size and oval to triangular shape.

Canned clams typically contain the meat from this mollusk.

Size: up to 225 mm; very common.

Northern quahog

Mercenaria mercenaria

The northern quahog has a thick, heavy shell, with highly visible ridges.

You'll find these in your local fish market, labeled as littlenecks, topnecks and cherrystones, depending on their size.

Size: up to 150 mm; very common.

Stout tagelus

Tagelus plebeius

The shell of the stout tagelus is rectangular or oval in shape, usually off-white in color.

Size: up to 118 mm; common.

Variable coquina

Donax variabilis

These are the little clams you often see burrowing back into the sand in large groups after a wave crashes ashore.

Coquinas come in various colors, from almost white, yellow, pink, orange, red, purple, to brownish and blueish, and some have darker "rays" on the inside of the shell.

Size: 13-20 mm; very common.

False angelwing or American piddock

Petricolaria pholadliformis

The false angelwing gets its name from its appearance: when both shells of this bivalve are intact, the pattern of ridges and ribs make them look like angel wings.

Size: 25-70 mm; common.

American mud snail or mud dog whelk

Tritia obsoleta

The American mud snail has a small, chalky white shell that is often discolored to a dark brown color due to its habitat, in muddy, intertidal areas and inlets.

Size: 18-25 mm; very common.

Threeline mudsnail

Tritia trivittata

The shell of the threeline mudsnail has a spindle shape, as well as distinct lines and ribs that give a bead-like texture.

Size: up to 20 mm; very common.

Bruised nassa

Phrontis vibex

The bruised nassa is a small shell shaped like a cone, with six or seven whorls.

Size: 10-20 mm.

Eastern auger

Terebra dislocata

The eastern auger is shaped like a unicorn horn, and is often pale gray or tan in color.

It only appears on the shores of New Jersey as a fossil, but commonly found from Maryland to Brazil.

Size: up to 57 mm; uncommon in New Jersey

Bay scallop

Argopecten irradians

The bay scallop has a fan-shaped shell with approximately 20 ribs, its natural color being more of a dark red.

Why is a bay scallop shell found on oceanside beaches? Dredging and beach replenishment are among the most common reasons.

Size: up to 95 mm; very common.

Sea scallop

Placopecten magellanicus

The sea scallop has a large, flat, fan-shaped shell.

The inside of the shell is glossy white with a muscular scar where the scallop was attached.

Size: 70-230 mm; typically found on New Jersey beaches after deep sea fisheries "drop" sea scallops close to shore.

Common jingle shell

Anomia simplex

The common jingle shell gets its name from the sound it makes: just pick up a few and shake them in your hand to hear them jingle!

This shell is very thin and brittle; the shiny shell often has a hole in the middle once its washed up onshore.

Size: 25-50 mm; very common.

Atlantic razor clam or Atlantic jackknife

Ensis leei

This clam is long and narrow with squared-off ends and has a slight curve in its shape.

Size: 100-200 mm; common.

Atlantic razor

Siliqua costata

The shell of the Atlantic razor is smooth, oblong and rounded at the ends. The shell is thin and fragile, with three light-colored "rays."

Size: 35-65 mm; very common.

Shark eye

Neverita duplicata

The shark eye is a type of moon snail, and has a dark "eye" at the tip of the spire.

The shark eye is commonly confused with the northern moonsnail: the shark eye has a patch of shell on the bottom which covers the hole in the center of the shell; the northern moonsnail's hole is not covered.

Size: 25-98 mm; very common.

Northern moonsnail

Euspira heros

The northern moonsnail can easily be differentiated from the similar shark eye by the uncovered hole at the center of the shell; the shark eye has a patch of shell covering the hole.

Size: 50-120 mm; very common.

Eastern oyster

Crassostrea virginica

The upper shell of the eastern oyster is thick and highly arched, and the lower shell is smoother and flat.

This mollusk is highly important to the environment: just one oyster can filter more than 50 gallons of water in 24 hours.

Size: 50-200 mm; very common.

Cross-hatched lucine

Divalinga quadrisulcata

The cross-hatched lucine has a circular-shaped shell and a distinct chevron-like pattern in its grooves.

Size: up to 25 mm.