Moon Shell (Shark Eye)
Phylum: Mollusca, Class: Gastropoda, Order: Littorinimorpha, Family: Naticidae, Genus: Neverita, Species: Neverita duplicata · Naticidae (Moon snail family) · Gastropod, whole shell, globular-spiral shape
Species
Neverita duplicata
Shell Type
Gastropod, whole shell, globular-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 3.5 inches.
Color & Pattern
Pale greyish-brown to tan on the upper body whorl, transitioning to a dark brownish-purple or chocolate-brown coloration around the umbilicus and inner spire. The surface is smooth with fine, faint growth lines.
Rarity
Common
Habitat
Found primarily in shallow marine waters on sandy intertidal and subtidal flats, often burrowing just beneath the surface of the sand.
Geographic Range
Western Atlantic Ocean, ranging from the coast of Massachusetts down through the Gulf of Mexico and into parts of South America.
Description
A sturdy, globular univalve shell featuring a low spire and a very large, inflated body whorl. The surface has a smooth, polished texture with subtle concentric growth lines. The prominent dark-stained umbilicus on the underside is partially or entirely covered by a thick, callus pad, giving it the characteristic 'shark eye' appearance when viewed from below.
Key Features
Globular shape with a very low spire, smooth polished surface, and a dark-colored callused umbilicus that distinguishes it from other naticids.
Collector Value
Low to moderate commercial value, highly popular among beginner beachcombers and casual shell collectors. Usually valued between $1 to $5 depending on size and condition.
Condition Notes
The shell appears to be in good to fine condition, completely intact with a smooth exterior finish and only minor natural wear.
Interesting Facts
Moon snails are predatory carnivores that drill circular holes into the shells of other bivalves using a specialized radula and acidic secretions to feed on the soft tissue inside.
Ecological Role
Acts as an apex predator among benthic molluscs, helping to regulate bivalve populations and maintain balance in the sandy marine ecosystem.
Similar Species
Atlantic Moon Shell (Neverita delessertiana) and other Naticidae species, which can be distinguished by differences in the size and color of the umbilical callus.
Beach Finding Tips
Look along sandy beaches at low tide, especially after strong storms or winter winds. Search for circular depressions in the sand or exposed sandbars where they burrow.