Shark Eye, Atlantic Moon Snail
Phylum: Mollusca, Class: Gastropoda, Order: Littorinimorpha, Family: Naticidae, Genus: Neverita, Species: Neverita duplicata · Naticidae (Moon Snail family) · Gastropod (univalve), whole shell, globular/spiral shape
Species
Neverita duplicata
Shell Type
Gastropod (univalve), whole shell, globular/spiral shape
Family
Naticidae (Moon Snail family)
Size
Approximately 2 to 2.5 inches in diameter; this is a mature specimen as the species typically ranges from 1 to 3.5 inches.
Color & Pattern
Pale tan to greyish-brown base; notable for a dark bluish-grey 'eye' spot at the center of the spire whorls. The surface shows light growth lines and is currently appearing sun-bleached and slightly weathered with some dark staining.
Rarity
Common; frequently found on beaches along the Eastern United States and Gulf Coast, though large, intact specimens with deep color are more sought after.
Habitat
Marine; found in intertidal and shallow subtidal zones, primarily in sandy substrates where it can burrow to hunt prey.
Geographic Range
Western Atlantic, stretching from Massachusetts to Florida, the Gulf of Mexico, and down to Brazil.
Description
A smooth, heavy, and globular shell characterized by its low spire and large body whorl. The surface is mostly smooth with subtle growth rings. The most striking feature is the central spire that resembles an eyeball. The aperture is large and semi-circular with a heavy callus covering the umbilicus.
Key Features
Lobular/circular shape, extremely large body whorl relative to spire, a dark blue-grey 'eye' at the apex, and a deep brown or grey umbilical callus that almost completely covers the hole.
Collector Value
Low; due to its abundance, it usually holds a value of $1-$5. However, it is a 'must-have' staple for any Atlantic coast collection due to its unique anatomical features.
Condition Notes
Fair to Good; the shell shows significant beach-wear and some calcification or staining on the spire. The glossy finish expected in live specimens has been matted by sand erosion and sun bleaching. No visible predator bore holes.
Interesting Facts
These snails are predatory 'drills' that use a radula to bore perfectly circular holes into the shells of clams and other bivalves. They also produce a unique 'sand collar' egg mass that looks like a rubbery ring of sand on the beach.
Ecological Role
Active predator that controls bivalve populations. They are also a primary food source for sea stars and larger crabs. Not currently a protected species.
Similar Species
Euspira heros (Northern Moon Snail) which lacks the dark 'eye' and has an open, deep umbilicus without the heavy callus.
Beach Finding Tips
Look for these in the 'wash' line at low tide or after a storm. They are often found partially buried in sand flats. Look for the distinctive circular shape among the rubble.