Shark's Eye, also known as Atlantic Moon Snail
Phylum: Mollusca, Class: Gastropoda, Order: Littorinimorpha, Family: Naticidae, Genus: Neverita, Species: Neverita duplicata · Naticidae (Moon Snail family) · Gastropod (snail/univalve), whole shell, globular and spiral shape
Species
Neverita duplicata (formerly Polinices duplicatus)
Shell Type
Gastropod (snail/univalve), whole shell, globular and spiral shape
Family
Naticidae (Moon Snail family)
Size
Approximately 1.5 to 2 inches in diameter, which is typical for a medium-sized adult. Adults generally range from 1 to 3 inches.
Color & Pattern
Smooth, glossy exterior featuring warm shades of tan, brown, and subtle grayish banding, with a darker brown or chestnut-colored umbilicus area. Colors appear natural and slightly weathered.
Rarity
Common, frequently found by beachcombers along sandy shores in its native range.
Habitat
Found in shallow marine waters, primarily in intertidal and subtidal zones down to moderate depths. Prefers sandy or muddy substrates where it burrows just beneath the sediment surface.
Geographic Range
Western Atlantic from Massachusetts southward along the coast of the United States, through the Gulf of Mexico.
Description
A classic globular, smooth-surfaced univalve shell with a low spire and a very large body whorl. The surface has a polished texture with faint growth lines. The aperture is wide and half-moon shaped, lacking teeth or spines, designed to accommodate the animal's large muscular foot.
Key Features
Globular, low-spired shape; smooth, polished surface; large body whorl; and a characteristic covered or partially filled umbilicus (navel) at the base of the shell.
Collector Value
Low to moderate commercial value. While very popular among casual beachcombers and beginner shell collectors, pristine large specimens hold modest value in shell shops.
Condition Notes
Good condition with a mostly intact surface and natural coloration. Minor surface wear and a small natural scar are visible, but the structure is solid. Collectibility grade: Good.
Interesting Facts
Moon snails are predatory carnivores that drill neat, circular holes into the shells of bivalves using an acidic secretion and a rasping radula to consume the soft tissue inside. Their egg masses, mixed with sand, form fragile, collar-like structures known as 'sand collars'.
Ecological Role
Acts as an apex predator in benthic soft-bottom communities, helping to regulate bivalve populations. They serve as food for various marine predators and fish when young.
Similar Species
Neverita lewisii (Lewis's Moon Snail), which is significantly larger and native to the Pacific coast; and Euspira heros (Northern Moon Snail), which is taller-spired and lighter in color.
Beach Finding Tips
Look along sandy beaches during low tide, especially after storms or heavy wave action. Search near sandbars or tidal flats where the water recedes to expose burrowing mollusks.