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, whole shell, globular or spherical shape
Species
Neverita duplicata
Shell Type
Gastropod, whole shell, globular or spherical shape
Family
Naticidae (Moon Snail family)
Size
Approximately 1.5 to 2 inches in diameter, which is average for this species. Adults typically range from 1 to 3 inches.
Color & Pattern
Smooth, polished exterior featuring a creamy grey to tan or light brown base color, often fading to a darker, rich chocolate brown or purplish-black at the distinct sunken umbilicus (the 'eye' center). The colors are natural and exhibit a smooth, glossy finish.
Rarity
Common, frequently found washed ashore along sandy beaches.
Habitat
Found in shallow marine waters, primarily in intertidal and subtidal zones down to moderate depths. Prefers sandy substrates and muddy bottoms where it burrows just beneath the surface.
Geographic Range
Western Atlantic from Massachusetts down to Florida, the Gulf of Mexico, and parts of the Caribbean.
Description
A classic globular, smooth-surfaced moon snail shell characterized by a low spire and a wide body whorl. The standout feature is the distinctive dark, spiral umbilicus centrally located on the underside, resembling an eerie, hypnotic eye. The shell texture is smooth and porcelain-like with fine growth lines.
Key Features
Globular shape, low spire, and a prominent, glossy dark callus that fills or partially fills the umbilicus, giving it the characteristic 'eye' appearance that separates it from other naticids.
Collector Value
Low to moderate value. While very popular for casual beachcombers and craft projects due to their striking 'eye' pattern, gem-quality or exceptionally large specimens are valued by specialized conchologists, typically selling for just a few dollars.
Condition Notes
The specimen appears to be in Good to Fine condition with a smooth, intact surface, well-preserved coloration, and a clearly defined central umbilicus with no major cracks or heavy erosion.
Interesting Facts
Shark's eyes are voracious predators that drill perfectly round, bevel-edged holes into the shells of bivalves using an acidic secretion and their radula to feed on the soft tissue inside. Their egg masses, mixed with sand, form distinctive curved structures known as 'sand collars'.
Ecological Role
Acts as an important carnivorous predator controlling bivalve populations in sandy marine ecosystems. They serve as food for various fish and larger marine carnivores, and their sand collars provide temporary habitat or food sources for other micro-organisms.
Similar Species
Other moon snails such as the Southern Moon Snail (Neverita delessertiana) or Northern Moon Snail (Euspira heros), distinguished by variations in umbilicus structure, callus size, and overall color tones.
Beach Finding Tips
Look along sandy ocean beaches during low tide, particularly after storms or heavy wave action. Search the wrack line or sift through shallow sand bars where they tend to burrow.