Shark Eye Moon Snail (also known as Northern 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, spiral shape
Species
Neverita duplicata
Shell Type
Gastropod (univalve), whole shell, spiral shape
Family
Naticidae (Moon Snail family)
Size
Approximately 1 to 1.5 inches in diameter, which is a medium-sized specimen. Adults typically range from 1 to 3 inches.
Color & Pattern
Smooth, polished exterior featuring a warm gradient from grayish-brown or tan on the body whorl to a rich, dark purple-brown or reddish-brown near the umbilicus. The apex and inner umbilical region show a characteristic dark purple-brown stain.
Rarity
Very Common, frequently found washed ashore on sandy beaches after storms or high tides.
Habitat
Shallow subtidal and intertidal zones, typically found buried just beneath the surface of sandy bottoms, mudflats, and sandbars in marine environments.
Geographic Range
Western Atlantic Ocean, ranging from Massachusetts south to Florida and the Gulf of Mexico, as well as along parts of the South American coast.
Description
A classic globular or hemispherical moon snail shell with a low spire and a large, rounded body whorl. The surface is smooth and glossy with fine growth lines. It features a characteristic deep, open umbilicus partly or largely filled with a heavy, dark-colored callus, giving it a distinctive 'eye-like' appearance.
Key Features
Globular shape, low spire, smooth glossy surface, and a prominent dark purple-brown umbilicus and callus region at the base, which distinguishes it from other naticid species.
Collector Value
Low to moderate collector value. They are very common beach finds and are frequently sold in shell shops or used in shell crafts, though large, pristine specimens are appreciated by beginning collectors.
Condition Notes
The specimen appears to be in Good to Fine condition with a smooth, intact body whorl and natural coloration, though minor beach wear and slight dulling may be present.
Interesting Facts
Moon snails are predatory carnivores that drill clean, countersunk holes into the shells of other bivalves using an acidic secretion and their radula to feed on the soft tissue within. The egg masses are laid in a mixture of sand and mucus, forming a distinctive, fragile collar shape known as a 'sand collar'.
Ecological Role
Acts as an important marine predator controlling bivalve populations in sandy benthic ecosystems. Their empty shells frequently provide crucial secondary habitat for hermit crabs.
Similar Species
Neverita lewisiana (Lewis's Moon Snail) which is generally much larger and lighter in color, and Euspira heros (Northern Moon Snail) which lacks the dark purple umbilicus.
Beach Finding Tips
Look along sandy beaches during low tide, particularly on sandbars or near tidal flats. Searching the wrack line after storms often reveals intact specimens buried just beneath the surface of loose sand.