Shark's Eye, also known as the 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, spiral shape
Species
Neverita duplicata
Shell Type
Gastropod (snail/univalve), whole shell, spiral shape
Family
Naticidae (Moon snail family)
Size
Approximately 1 to 1.5 inches in diameter, which is on the smaller side for this species. Adults typically range from 1.5 to 3 inches.
Color & Pattern
Brownish-grey base color with a darker, chocolate-brown to reddish-brown umbilicus area and shoulder. The surface is smooth and glossy with subtle growth lines. The colors appear natural and slightly damp, giving it a polished sheen.
Rarity
Common, frequently found washed up on sandy beaches along the Atlantic and Gulf coasts.
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 Ocean, ranging from the coast of Massachusetts down through the Gulf of Mexico, Florida, and the Caribbean to Brazil.
Description
A globular, smooth, and sturdy univalve shell with a low spired apex and a large, rounded body whorl. The surface is polished and tactile, featuring a characteristic closed or partially covered umbilicus with a distinct callus pad. The aperture is wide and half-moon shaped, lacking the operculum in this particular specimen.
Key Features
Globular shape, low spire, smooth glossy finish, and a distinct callus filling or partially covering the umbilicus region at the base, differentiating it from other moon snail species.
Collector Value
Low to moderate commercial value, highly popular among beginner beachcombers and casual shell collectors. Typically valued as a common souvenir find worth a few dollars, though large, pristine specimens can be more desirable.
Condition Notes
Good condition for a beach find. The shell is intact with minimal surface wear, though there are minor pitting marks near the apex and aperture. Retains good natural coloration and polish, grading as a Fine collector piece.
Interesting Facts
Moon snails are predatory carnivores that hunt bivalves. They drill a perfectly round, bevel-edged hole into the shell of their prey using a specialized radula and acidic secretions, then consume the soft tissue inside. Their egg masses, known as 'sand collars', are made of sand glued together with mucus.
Ecological Role
Acts as an important top predator in sandy bottom marine ecosystems, helping to regulate bivalve populations. They serve as a food source for various marine animals, and their abandoned shells frequently provide homes for hermit crabs.
Similar Species
Neverita lewisii (Lewis's Moon Snail) which is generally larger and lighter in color, and Polinices mammatus, which features different umbilical characteristics.
Beach Finding Tips
Look along sandy ocean beaches and barrier islands, especially at low tide or immediately following storms. Scan the damp sand near the surf line or look for the characteristic 'sand collars' which indicate living populations nearby.