Bleeding Tooth Operculum (Alternate: Nerite Door/Lid)
Phylum: Mollusca, Class: Gastropoda, Order: Cycloneritida, Family: Neritidae, Genus: Nerita, Species: Nerita peloronta · Neritidae (Nerite family) · Operculum (The calcareous "door" or lid of a Gastropod shell)
Species
Nerita peloronta (Likely identification)
Shell Type
Operculum (The calcareous "door" or lid of a Gastropod shell)
Family
Neritidae (Nerite family)
Size
Approximately 10-15mm (0.4-0.6 inches). This is consistent with an adult specimen of this species.
Color & Pattern
Creamy beige to off-white base color with a distinct granulated texture. One side features a characteristic orange-red or pinkish stain near the hinge/articulation point, which gives it the "bleeding" common name.
Rarity
Common (Beachcombing find). While the snails are abundant, the opercula are small and often overlooked in shell hash.
Habitat
Intertidal zone. Found on rocky shorelines, often clustered in crevices where they are exposed to heavy wave action and air during low tide.
Geographic Range
Tropical Western Atlantic; common in Florida, the Caribbean (including Cancun/Yucatan), and Bermuda.
Description
This is a calcareous operculum, a hard 'trapdoor' used by the snail to seal itself inside its shell for protection and moisture retention. It is semi-circular or D-shaped with a pebbled, granulated exterior surface. The inner surface is smooth and features a small peg or hook (apophysis) used for muscle attachment.
Key Features
D-shaped outline; granulated exterior; distinct orange-red stain near the straight edge; solid calcareous (calcite) composition rather than proteinaceous.
Collector Value
Low monetary value ($0.50 - $1.00), but high interest for educational collections. Most collectors seek the complete shell with the operculum still attached.
Condition Notes
Fair to Good. The specimen is beach-worn with rounded edges and some oxidation/fading of the red pigment. It is a separate anatomical part, not the whole shell.
Interesting Facts
The 'Bleeding Tooth' snail is so named because of the red-stained 'teeth' on the columella of its shell. Ancient Caribbean cultures sometimes used these durable opercula as beads or decorative elements.
Ecological Role
The operculum serves as a critical defense against predators like crabs and prevents desiccation (drying out) when the snail is exposed to the tropical sun at low tide.
Similar Species
Nerita versicolor (Four-toothed Nerite) opercula are similar but usually lack the vivid orange-red stain and have different granulation patterns.
Beach Finding Tips
Look in 'shell hash' lines near rocky outcrops or limestone shorelines in Cancun. They often accumulate in the tide pools or at the high-tide mark where small debris settles.
Notes
Cancun