Shark Eye, also known as the Northern 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 globular, globose shape
Species
Neverita duplicata
Shell Type
Gastropod univalve, whole shell with a globular, globose shape
Family
Naticidae (Moon snail family)
Size
Approximately 1.5 to 2 inches in diameter, which is moderate for this species. Adults typically range from 1.5 to 3 inches.
Color & Pattern
Warm beige to golden-brown base color featuring a distinctive pattern of fine, darker brown speckles and mottled markings that often fade toward the spire. The coloration is natural with slight sun-bleaching on the prominent callus area.
Rarity
Common, frequently found by beachcombers along sandy shores and tidal flats.
Habitat
Found primarily in shallow marine waters, intertidal zones, and subtidal areas down to moderate depths. Prefers sandy substrates where it burrows just beneath the surface to hunt for prey.
Geographic Range
Western Atlantic Ocean, ranging from the coast of Massachusetts down to Florida and into the Gulf of Mexico.
Description
A sturdy, smooth, globular shell with a low, inconspicuous spire and a large body whorl. The surface features faint growth lines and a rich, speckled brown and tan pattern. It possesses a heavy, glazed callus that partially or fully obscures the umbilicus, a hallmark of the species.
Key Features
Globular shape, low spire, smooth polished surface, and a heavy callus over the umbilical region that is typically dark brown or chocolate-colored.
Collector Value
Low to moderate commercial value, but highly popular among casual beachcombers and beginner shell collectors due to their pleasing, smooth shape and attractive patterns. Typically worth just a few dollars.
Condition Notes
Good condition with natural coloration intact and minimal wear. There is a minor natural stress crack visible along the body whorl, but the overall structural integrity remains sound for a beach-found specimen. Grade: Good.
Interesting Facts
Moon snails are predatory carnivores that drill clean, countersunk holes into the shells of bivalves using a specialized radula and acidic secretions to consume the soft tissue inside. They create sand collars to house their egg masses.
Ecological Role
Acts as an important marine predator helping to control bivalve populations in sandy benthic ecosystems. They serve as food for various marine mammals, large fish, and sea birds.
Similar Species
Neverita lewisiana (Lewis's Moon Snail), which is generally larger and lighter in color, and Polinices uberinus, which lacks the distinct heavy dark callus of the Shark Eye.
Beach Finding Tips
Look along sandy ocean beaches and barrier islands, especially at low tide. Search near sandbars or look for the characteristic 'sand collars' (egg masses) which often indicate moon snails are active nearby.