Shark Eye Moon Snail (Alternate: Northern Moon Snail, Shark's Eye)
Phylum: Mollusca, Class: Gastropoda, Order: Littorinimorpha, Family: Naticidae, Genus: Neverita, Species: N. duplicata · Naticidae (Moon Snail family) · Gastropod (univalve), whole shell, globose or spherical shape with a low spire
Species
Neverita duplicata (formerly Polinices duplicatus)
Shell Type
Gastropod (univalve), whole shell, globose or spherical shape with a low spire
Family
Naticidae (Moon Snail family)
Size
Approximately 1 inch in diameter, which is on the smaller side. Adult specimens typically range from 1.5 to 3 inches.
Color & Pattern
Uniform glossy off-white to pale cream coloration with subtle growth lines. The specimen appears sun-bleached and worn, lacking the typical brownish-gray exterior or the characteristic dark brown or purplish callus found near the umbilicus.
Rarity
Very Common. These shells and their egg collars (sand collars) are frequently encountered by beachcombers along the eastern and gulf coasts of the United States.
Habitat
Found in shallow marine waters, intertidal and subtidal zones down to moderate depths. Prefers sandy or muddy substrates where it burrows just beneath the surface to hunt other mollusks.
Geographic Range
Western Atlantic Ocean, ranging from Massachusetts down to the Gulf of Mexico, Florida, and parts of the Caribbean.
Description
A smooth, rounded, globose gastropod shell with a low, flattened spire and a large body whorl. The surface is mostly smooth except for faint, fine growth lines. The aperture is large and semicircular, though the base is partially obscured in the image, showing the compact, rounded profile characteristic of moon snails.
Key Features
Globose shape with a very low spire, smooth porcelain-like texture, large body whorl, and a characteristic thick callus partially or fully covering the umbilicus depending on the exact species variant.
Collector Value
Low collectible value due to its abundance and worn, bleached condition. It is a common educational shell rather than a prized specimen, typically valued at pennies or collected freely by beachcombers.
Condition Notes
Fair to Good condition. The shell is structurally intact without major fractures, but it is heavily sun-bleached with a worn, matte surface texture, having lost its natural outer layer and original coloration.
Interesting Facts
Moon snails are formidable predators. They drill a perfectly round, bevel-edged hole into the shells of other bivalves using a specialized radula and acidic secretions, then feed on the soft tissue inside. They are also famous for creating 'sand collars'—egg masses cemented together with sand grains.
Ecological Role
Acts as a primary carnivorous predator in benthic marine ecosystems, helping to regulate populations of clams and other bivalves. They serve as food for various marine scavengers and fish, while their discarded shells provide important temporary homes for hermit crabs.
Similar Species
Atlantic Moon Snail (Euspira lewisii or Polinices borchianis) and Neverita చీreata. Distinguished by size, spire height, and the exact shape and coloration of the umbilical callus.
Beach Finding Tips
Look along sandy ocean beaches during low tide, especially after a storm or strong wave action. Also keep an eye out for 'sand collars' (fragile, collar-shaped sand structures) which indicate moon snails are active in the area.