Shark Eye Operculum (Cat's Eye)
Phylum: Mollusca, Class: Gastropoda, Order: Littorinimorpha, Family: Naticidae, Genus: Neverita, Species: Neverita duplicata · Naticidae (Moon Snail family) · Gastropod operculum (calcified trapdoor)
Species
Neverita duplicata (likely, operculum)
Shell Type
Gastropod operculum (calcified trapdoor)
Family
Naticidae (Moon Snail family)
Size
Approximately 0.5 to 0.75 inches, typical for an operculum of a medium-sized moon snail.
Color & Pattern
Dark brown to nearly black coloration with a thick, smooth, porcelain-like texture on the outer surface.
Rarity
Common
Habitat
Sandy bottoms in shallow marine waters where moon snails burrow to hunt bivalves.
Geographic Range
Western Atlantic and Gulf of Mexico, depending on the specific moon snail species.
Description
A thick, calcified operculum that acts as a protective trapdoor for a moon snail. It is oval to ear-shaped with concentric growth rings.
Key Features
Calcareous composition, thick dark brown exterior, smooth texture, and concentric growth lines.
Collector Value
Low commercial value, though interesting as a beachcombing curiosity or educational specimen.
Condition Notes
Good condition. Solid and intact, showing natural wear consistent with beach drift.
Interesting Facts
The operculum is secreted by the foot of the snail and is used to seal the animal inside its shell when threatened or during low tide.
Ecological Role
Moon snails are key carnivorous predators in sandy intertidal and subtidal marine ecosystems, drilling holes into bivalve shells to feed.
Similar Species
Opercula from other naticid species such as Euspira heros or Polinices species.
Beach Finding Tips
Look along the wrack line on sandy beaches, particularly after storms when heavy shell debris washes ashore.