Shark Eye (also known as Northern Moon Snail)
Phylum: Mollusca, Class: Gastropoda, Order: Littorinimorpha, Family: Naticidae, Genus: Neverita, Species: Neverita duplicata · Naticidae (Moon Snail family) · Gastropod (univalve), whole shell, globular and smooth shape
Species
Neverita duplicata (formerly Polinices duplicatus)
Shell Type
Gastropod (univalve), whole shell, globular and smooth shape
Family
Naticidae (Moon Snail family)
Size
Approximately 1.5 to 2 inches in diameter, which is typical for a medium-sized specimen. Adults can range from 1 to 3 inches.
Color & Pattern
Smooth, glossy finish with shades of grayish-brown, tan, and cream. The central area or callus near the umbilicus features a characteristic dark brown or purplish stain, giving it a distinctive 'eye' appearance.
Rarity
Common
Habitat
Found in shallow marine waters, primarily on sandy intertidal and subtidal flats, where they burrow just beneath the surface in search of prey.
Geographic Range
Western Atlantic coast from Massachusetts down to Florida and the Gulf of Mexico.
Description
A sturdy, globular marine snail shell with a low spire and a very wide body whorl. The surface is smooth and polished with fine growth lines. The aperture is large and semi-circular, and the distinctive heavy, dark callus partially or completely fills the umbilicus.
Key Features
Globular shape with a low spire, smooth glossy surface, and a heavy, dark-colored umbilical callus that distinguishes it from other moon snail species.
Collector Value
Inexpensive and widely available, typically worth a few dollars, making it a staple and popular find for beginning beachcombers rather than an investment piece.
Condition Notes
Good condition whole shell. The surface maintains a natural gloss with minor wear. The apex is intact and the aperture lip is mostly smooth, qualifying as a Fine grade collector specimen.
Interesting Facts
Moon snails are predatory carnivores that drill circular holes into the shells of bivalves using an acidic secretion and their radula to consume the soft tissue inside.
Ecological Role
Acts as an apex invertebrate predator in soft-bottom benthic communities, regulating bivalve populations and providing drilled empty shells as shelter for hermit crabs.
Similar Species
Lesser Moon Snail (Euspira lewisii or Neverita interrupta), which can be differentiated by umbilical structure and geographical range.
Beach Finding Tips
Look along sandy beaches at low tide, particularly near sandbars or areas where surf clam shells with neat drilled holes are found.