Shark Eye Moon Snail (also known as the Northern Moon Snail or Atlantic Moon Snail)
Phylum: Mollusca, Class: Gastropoda, Order: Littorinimorpha, Family: Naticidae, Genus: Neverita, Species: Neverita duplicata · Naticidae (Moon Snail family) · Gastropod (univalve snail), whole shell, globose or spherical spiral shape
Species
Neverita duplicata (formerly Polinices duplicatus)
Shell Type
Gastropod (univalve snail), whole shell, globose or spherical spiral shape
Family
Naticidae (Moon Snail family)
Size
Approximately 1 to 1.5 inches in diameter based on visual scale, which is on the smaller to medium side. Adults typically range from 1.5 to 3 inches.
Color & Pattern
Smooth, glossy finish featuring brownish-grey, tan, and cream tones with characteristic darker purplish-brown coloration centered around the obscured umbilicus area. The colors appear natural with a slight polish from wave action.
Rarity
Very Common. Frequently found washed ashore on sandy beaches throughout its range.
Habitat
Found primarily in shallow subtidal and intertidal zones, buried beneath sandy substrates where they hunt for bivalve prey. Marine environment.
Geographic Range
Western Atlantic Ocean, ranging from Massachusetts south to Florida and the Gulf of Mexico.
Description
A sturdy, globular, low-spired marine snail shell with a smooth, polished porcelain-like exterior. The aperture is wide and semi-circular, and the spire is very flat and compressed against the large final body whorl.
Key Features
Low, flattened spire, smooth globose body whorl, and a characteristic dark brown callus patch covering the umbilicus region on the underside.
Collector Value
Low commercial value due to high abundance, though prized by beginning beachcombers and used extensively in shell crafts.
Condition Notes
Fair to Good condition. The shell is intact with a nice natural gloss, though showing some minor wear and slight fading typical of beach-worn specimens. Collectibility grade: Fair.
Interesting Facts
Moon snails hunt by drilling a perfectly round, countersunk hole into the shells of bivalves using an acidic secretion and a radula, then feeding on the soft tissue inside. They also create sand collars—egg masses made of sand glued together with mucus.
Ecological Role
Acts as an active carnivorous predator controlling bivalve populations in sandy benthic ecosystems. Serves as food for various marine predators and fish.
Similar Species
Atlantic Moon Snail (Euspira heros), which is taller and has a distinct open umbilicus without the heavy dark callus pad found in Neverita duplicata.
Beach Finding Tips
Look along sandy intertidal zones at low tide, or search the wrack line after storms where whole specimens and sand collars wash ashore.