Bleeding Tooth or Virgin Nerite (Operculum)
Phylum: Mollusca, Class: Gastropoda, Order: Cycloneritida, Family: Neritidae, Genus: Nerita · Neritidae (Nerite family) · Gastropod Operculum (the 'trapdoor' of a snail). Shape: Semi-circular/D-shaped with a slight peak.
Species
Nerita peloronta or Nerita tessellata (Likely Operculum)
Shell Type
Gastropod Operculum (the 'trapdoor' of a snail). Shape: Semi-circular/D-shaped with a slight peak.
Family
Neritidae (Nerite family)
Size
Approximately 12-15mm (0.5 inches). This is a standard size for an adult large Nerite found in the Caribbean.
Color & Pattern
Pure white to creamy white. Appears sun-bleached or naturally calcified. One side is flat and smooth (worn), while the other shows a subtle pucker or granulations characteristic of the genus.
Rarity
Common. While the snails are abundant, the detached opercula are often overlooked by beachcombers as white pebbles.
Habitat
Found in high-energy intertidal zones, specifically on wave-beaten rocks and in rocky crevices. They are salt-water marine snails.
Geographic Range
Tropical Western Atlantic, specifically common in the Caribbean Sea (including Cancun), Florida, and the Gulf of Mexico.
Description
This is a calcified operculum, often called a 'sea bean' or 'cat's eye' by locals (though true Cat's Eyes come from Turbans). It is a stony, D-shaped structure used by the snail to seal its shell against predators and desiccation. This specimen is heavily water-worn, giving it a smooth, pebble-like appearance.
Key Features
Planoconvex (flat on one side, domed on the other) shape, D-shaped silhouette, stony calcareous composition, and a small internal peg (if flipped) used for muscle attachment.
Collector Value
Minimal monetary value ($0.50 - $1.00). It is primarily a souvenir or 'curiosity' piece rather than a high-end specimen due to its worn condition.
Condition Notes
Worn/Fair. The specimen is heavily eroded by wave action, which has removed the characteristic 'blood' red or black coloration found on fresh 'Bleeding Tooth' opercula. It is a 'beach-worn' specimen.
Interesting Facts
The Nerita peloronta is famous for the 'Bleeding Tooth' shell, which has red stains on the columella. The operculum acts as a protective shield, allowing the snail to survive several days out of water by trapping moisture inside the shell.
Ecological Role
The living snail is a grazer that controls algae growth on rocky shores. The operculum is a critical defense mechanism against crabs and birds. No current conservation concerns.
Similar Species
Turban shell opercula (which are more circular/swirled) and rounded pieces of white coral or quartz water-smoothed into 'sea stones'.
Beach Finding Tips
Look in the 'wrack line' or in tide pools near rocky jetties and limestone outcroppings in Cancun. They blend in with white coral fragments.
Notes
Cancun