Shark's Eye, Moon Snail, or Atlantic Moon Snail
Phylum: Mollusca, Class: Gastropoda, Order: Littorinimorpha, Family: Naticidae, Genus: Neverita, Species: Neverita duplicata · Naticidae (Moon Snail family) · Gastropod (univalve); whole shell with a globose, spiral shape
Species
Neverita duplicata
Shell Type
Gastropod (univalve); whole shell with a globose, spiral shape
Family
Naticidae (Moon Snail family)
Size
Approximately 1.5 to 2 inches (3.8 - 5 cm) in diameter. This is a medium-sized specimen, as adults typically reach 3 inches.
Color & Pattern
Smooth, glossy exterior with a base color of soft tan to grayish-lavender. The spire shows a distinct dark brown or 'eye-like' center. There are subtle growth lines and faint white banding following the whorls. The color appears natural but slightly matte, suggesting it may have been beach-worn.
Rarity
Very Common; these are frequently found washed up on Atlantic and Gulf Coast beaches.
Habitat
Intertidal and shallow subtidal zones, primarily in sandy substrates where they can burrow just beneath the surface to hunt for prey.
Geographic Range
Western Atlantic coast from Massachusetts to Florida, and throughout the Gulf of Mexico.
Description
A smooth, rounded shell with a low spire and a very large body whorl. The surface is polished and lacks heavy ribbing or spines, adapted for easy movement through sand. The most striking feature is the central spire, which resembles a pupil, giving the shell its 'Shark's Eye' moniker. The aperture is large and semi-circular.
Key Features
Globose shape, smooth texture, and the presence of a large, flat umbilical callus (a button-like growth near the opening) which distinguishes it from other moon snails like the Northern Moon Snail.
Collector Value
Low monetary value (usually $1 - $5) due to high abundance, but highly desired by amateur collectors for its unique aesthetic and 'eye' appearance. Large, 'gem-quality' specimens with high gloss are more prized.
Condition Notes
The shell appears to be in 'Good' condition. It is largely intact but shows signs of beach erosion (weathering) on the spire and some thinning around the outer lip. The loss of the high-gloss shine indicates it has been tumbled in the surf.
Interesting Facts
Moon snails are predatory carnivores. They use a specialized tongue-like organ called a radula to drill perfectly circular holes into the shells of clams and other bivalves to consume the occupant. They also lay eggs in unique 'sand collars' that look like discarded pieces of grey plastic or rubber on the beach.
Ecological Role
Aggressive predator of bivalves, helping to regulate clam and cockle populations. It is a vital part of the sandy-bottom food web and its empty shells often provide homes for large hermit crabs.
Similar Species
Euspira heros (Northern Moon Snail), which is larger, lacks the dark 'eye' center, and does not have the flat umbilical callus characteristic of Neverita duplicata.
Beach Finding Tips
Search at low tide on sandy flats or near the shoreline after a storm. Look for the rounded tops of the shells poking through the wet sand or check the 'wrack line' where debris collects.