Shark Eye, Atlantic Moon Snail
Phylum: Mollusca, Class: Gastropoda, Order: Littorinimorpha, Family: Naticidae, Genus: Neverita, Species: Neverita duplicata · Naticidae (Moon Snail family) · Gastropod (univalve); Spiral/Globose whole shell
Species
Neverita duplicata
Shell Type
Gastropod (univalve); Spiral/Globose whole shell
Family
Naticidae (Moon Snail family)
Size
Approximately 1.5 to 2 inches in diameter. This specimen appears to be sub-adult, as the species typically ranges from 1 to 3.5 inches.
Color & Pattern
Base color is predominantly creamy white to light grey/blue. The apex (the 'eye') shows a characteristic dark grey-brown circle. The interior aperture is typically a chocolate brown or deep tan, though it is not visible in this orientation.
Rarity
Common; frequently found on sandy beaches after storms or at low tide.
Habitat
Marine; found in intertidal and shallow subtidal zones. Prefers sandy substrates where it can burrow to hunt for prey.
Geographic Range
Western Atlantic, extending from Massachusetts to the Gulf of Mexico and down to Brazil.
Description
A smooth, globose, and heavy shell known for its low spire and large body whorl. The surface is polished and lacks prominent sculpture, favoring a hydrodynamic shape for burrowing through sand. The most striking feature is the dark umbilical callus that resembles an eye.
Key Features
Low, flattened spire; large, rounded body whorl; smooth texture; and most notably, the prominent brown callus that partially covers the umbilicus.
Collector Value
Low; primarily valued as a 'starter' shell for new collectors or for craft use due to its abundance. Large, perfectly polished 'gem' specimens with deep purple or brown interiors may hold slightly more value ($2–$5).
Condition Notes
Fair to Good. The image is blurred, but the shell appears intact with minimal chipping. The color looks slightly weathered or sun-bleached, suggesting it was found washed up rather than collected live.
Interesting Facts
The Atlantic Moon Snail is a predatory carnivore that uses its radula to drill perfectly circular holes into the shells of clams and other mollusks to consume them. They produce unique egg cases known as 'sand collars,' which are made of sand and mucus.
Ecological Role
Key predator in sandy benthos environments, helping to regulate the populations of bivalves. They are in turn eaten by sea stars, crabs, and larger gastropods.
Similar Species
Euspira heros (Northern Moon Snail) which lacks the dark callus over the 'eye' and has a deeper umbilicus.
Beach Finding Tips
Look for these on sandy flats during extremely low tides or after winter storms. Look for the 'sand collars' nearby, as they indicate a healthy population in the area.