Moon Snail or Shark Eye (Common Atlantic Moon Snail)
Phylum: Mollusca, Class: Gastropoda, Order: Littorinimorpha, Family: Naticidae, Genus: Neverita, Species: Neverita duplicata · Naticidae (Moon Snail family) · Gastropod (univalve), whole shell, globose or spiral shape
Species
Neverita duplicata
Shell Type
Gastropod (univalve), whole shell, globose or spiral shape
Family
Naticidae (Moon Snail family)
Size
Approximately 2 to 3 inches in diameter, which is typical for an adult specimen of this species. Adults generally range from 1.5 to 4 inches.
Color & Pattern
Muted grayish-brown to tan exterior with a slightly darker brownish-purple umbilicus area. The surface shows significant weathering, calcium encrustation, and sun-bleaching, revealing lighter undertones.
Rarity
Common
Habitat
Found in marine environments, typically inhabiting shallow subtidal and intertidal zones down to moderate depths. Prefers sandy or muddy substrates where it can easily burrow.
Geographic Range
Western Atlantic Ocean, ranging from Massachusetts down to the Gulf of Mexico, Florida, and the Caribbean, as well as parts of South America.
Description
A sturdy, globose marine snail shell with a low, flattened spire and a large, wide body whorl. The surface texture is smooth underneath weathering, featuring fine growth lines. The aperture is large and semicircular, and the distinctive callus covers the umbilicus.
Key Features
Globose, low-spired shape; large body whorl; smooth surface; and a characteristic heavy callus partially or fully covering the central umbilicus.
Collector Value
Low to moderate value. While very popular among casual beachcombers, weathered or beach-worn specimens have little monetary value and are typically valued as personal keepsakes rather than commercial collector pieces.
Condition Notes
Fair condition. The shell is structurally intact with no major fractures, but it exhibits heavy surface wear, calcium deposits, and pitting from natural elements and age, giving it a weathered beach-worn appearance.
Interesting Facts
Moon snails are predatory carnivores that drill circular holes into the shells of bivalves using an acidic secretion and a radula to consume the soft tissue inside. Their egg masses, known as "sand collars," are formed of sand glued together with mucus.
Ecological Role
Acts as an important apex predator among benthic mollusks, regulating bivalve populations. They serve as food for various marine predators, and their vacated shells frequently provide homes for hermit crabs.
Similar Species
Neverita lewisii (Lewis's Moon Snail), which is larger and generally found on the Pacific coast, and Euspira heros (Northern Moon Snail), which is taller-spired and has an open umbilicus.
Beach Finding Tips
Look along sandy beaches at low tide, particularly after storms or heavy wave action. Search the swash zone or sandy tidal flats where moon snails burrow just beneath the surface.