Shark Eye, Atlantic Moon Snail, Northern Moon Snail
Phylum: Mollusca, Class: Gastropoda, Subclass: Caenogastropoda, Order: Littorinimorpha, Superfamily: Naticoidea, Family: Naticidae, Genus: Neverita, Species: Neverita duplicata · Naticidae (Moon Snail family) · Gastropod (univalve snail); complete whole shell; globose, low-spired spherical shape.
Species
Neverita duplicata (formerly Polinices duplicatus)
Shell Type
Gastropod (univalve snail); complete whole shell; globose, low-spired spherical shape.
Family
Naticidae (Moon Snail family)
Size
Approximately 1.0 to 1.25 inches (25-32 mm) in diameter, which is a small-to-medium specimen for this species. Adults typically range from 1 to 3 inches (25-75 mm).
Color & Pattern
Smooth, polished exterior featuring warm honey-amber, golden-yellow, and light tan coloration with subtle spiral banding. The apex/spire exhibits a darker brown focal point surrounded by lighter rings, creating the classic 'eye' appearance. The glossy, water-worn texture indicates beach exposure.
Rarity
Common to Very Common along the US Atlantic coast, particularly on sandy beaches in North Carolina.
Habitat
Shallow marine waters, intertidal sand flats, mudflats, and subtidal sandy bottoms down to depths of about 180 feet (55 m). Live animals plow just beneath the sand surface.
Geographic Range
Western Atlantic Coast of North America, ranging from Cape Cod, Massachusetts down through North Carolina (including Oak Island) to Florida, the Gulf of Mexico, and the Caribbean.
Description
A beautiful, highly polished, button-shaped gastropod shell viewed from the apical aspect. The smooth body whorl expands rapidly from a central brown spiral apex that resembles a mammal or eye structure. The surface is exceptionally smooth with fine growth lines, and the shell displays rich golden-amber translucency due to gentle wave action and polishing.
Key Features
Depressed, low spire; glossy, smooth exterior without heavy sculpture; dark central brown apex resembling a pupil/eye; presence of a distinctive purple-brown callus partially or completely covering the umbilicus on the ventral side.
Collector Value
Low to Moderate monetarily ($1-$5 for standard beach finds), but highly valued by beachcombers for its aesthetic 'shark eye' apical view and glossy texture.
Condition Notes
Good to Fine condition. The exterior exhibits nice natural polish and vivid golden coloration without major cracks or chips. Minor natural wave wear gives it a rounded, gem-like appearance. Collectibility Grade: Fine.
Interesting Facts
Moon snails are voracious predatory snails that hunt bivalves underground. They drill neat, countersunk, cone-shaped holes into clam shells using their radula and digestive acid. Females lay eggs encased in flexible sand collar rings held together by mucus.
Ecological Role
Key benthic predator that controls populations of clams, mussels, and other bivalves. Shells serve as crucial homes for hermit crabs after the snail dies. The species is common and not protected.
Similar Species
Euspira heros (Northern Moon Snail, which lacks the prominent umbilical callus and distinct dark central eye patterning) and Sinum perspectivum (White Baby's Ear, which is flatter and ear-shaped).
Beach Finding Tips
Look along low-tide wrack lines, tidal inlets, and sandbars after storms or during spring low tides on North Carolina beaches like Oak Island and Bald Head Island.
Notes
Oak Island NC