Shark Eye, Atlantic Moon Snail
Phylum: Mollusca, Class: Gastropoda, Order: Littorinimorpha, Family: Naticidae, Genus: Neverita, Species: Neverita duplicata · Naticidae (Moon Snail family) · Gastropod (univalve); Spiral/Globose whole shell
Species
Neverita duplicata
Shell Type
Gastropod (univalve); Spiral/Globose whole shell
Family
Naticidae (Moon Snail family)
Size
Approximately 2.5 to 3 inches in diameter; this is a large adult specimen, as the typical range is 1 to 3.5 inches.
Color & Pattern
Glossy exterior with a creamy tan to grey base color. Notable for its 'eye-like' appearance at the apex, featuring concentric rings of gold, brown, and dark blue-grey. The body whorl shows subtle growth lines and a smooth, polished finish. The interior (though not fully visible) typically features a large, dark brown callus.
Rarity
Common; frequently found on sandy beaches after high tides or storms, though large, unweathered specimens are more prized.
Habitat
Marine; intertidal and shallow subtidal zones. Prefers sandy substrates where it can burrow to hunt for prey.
Geographic Range
Western Atlantic, ranging from Massachusetts south to Florida and the Gulf of Mexico, extending down to Brazil.
Description
A classic globose shell with a smooth, polished texture and low spire. The shell is remarkably robust and heavy for its size. Its most attractive feature is the swirling apex that mimics the pupil and iris of an eye. The body whorl is expansive, ending in a wide aperture that is largely covered by a thick, dark brown umbilical callus.
Key Features
Low, flattened spire compared to other moon snails; presence of a large, dark brown umbilical callus that almost completely covers the umbilicus; smooth, glossy surface lacking distinct ribs.
Collector Value
Modest collector value ($2-$10). While common, specimens with dark, vivid 'eyes' and intact gloss are staples for any geographic collection of North American shells.
Condition Notes
Fine to Excellent. The gloss is well-preserved, suggesting it was found recently or protected from heavy surf. There is minor surface pitting near the suture and a small patch of encrustation/erosion, but the apex is intact.
Interesting Facts
These snails are active predators that hunt other mollusks by drilling perfectly circular holes into their shells using a radula and sulfuric acid. They lay their eggs in distinctive 'sand collars,' which are rubbery rings made of sand and mucus that wash up on beaches in the spring.
Ecological Role
Major predator of bivalves; they help regulate clam and cockle populations. They are in turn eaten by sea stars, crabs, and larger predatory snails like Whelks.
Similar Species
Euspira heros (Northern Moon Snail) which lacks the dark brown callus and has a more open umbilicus; Neverita delessertiana which has a divided callus.
Beach Finding Tips
Look along the wrack line (the line of debris left by high tide) on sandy Atlantic beaches. They are easiest to find during extreme low tides when they may leave 'crawling trails' in wet sand.