Checkered Nerite (heavily eroded)
Phylum: Mollusca, Class: Gastropoda, Order: Cycloneritida, Family: Neritidae, Genus: Nerita, Species: Nerita tessellata · Neritidae (Nerite family) · Gastropod (univalve); globose/semispherical shape
Species
Nerita tessellata
Shell Type
Gastropod (univalve); globose/semispherical shape
Family
Neritidae (Nerite family)
Size
Approximately 12-18mm in diameter. This is within the average adult size range of 0.5 to 0.75 inches for this species.
Color & Pattern
Base color is off-white to cream with faint remnant patches of orange-pink and black speckling. The original bold black-and-white checkered pattern has been almost entirely removed by wave action and sun-bleaching.
Rarity
Very Common
Habitat
Intertidal zone, typically found clinging to rocks in the high-tide splash zone. Extremely common in rocky shorelines of the Caribbean.
Geographic Range
Western Atlantic: Florida, Bermuda, and throughout the Caribbean (including Cancun, Mexico) to Brazil.
Description
This is a sturdy, globose gastropod shell that has been heavily water-worn. It features a low spire and a broad body whorl. In its current state, the distinctive exterior sculptural ribs and black checkering are smoothed down, giving it a pebble-like appearance. The aperture is semi-circular, characteristic of the Nerita genus.
Key Features
Hemispherical shape with a flat base (aperture side), thick shell walls designed to withstand heavy surf, and a distinctively toothed outer lip and columella (though these are obscured in the image).
Collector Value
Minimal monetary value (less than $1). Its value is primarily educational or sentimental as it represents a ubiquitous part of the Caribbean marine ecosystem.
Condition Notes
Poor to Fair (Beach-worn). The shell is heavily eroded ('beach-rolled'), resulting in the loss of surface sculpture and primary pigmentation. It lacks professional collector value but serves as a sentimental souvenir from Cancun.
Interesting Facts
Nerites are 'intertidal survivors' that can seal themselves against rocks with an operculum to retain moisture during low tide. They are primarily nocturnal grazers that feed on algae.
Ecological Role
Important herbivore in the rocky intertidal ecosystem, helping to control algae growth and providing a food source for shorebirds and crabs.
Similar Species
Nerita fulgurans (Antillean Nerite) which is larger with finer ribs, and Nerita versicolor (Four-toothed Nerite) which usually has red tints near the teeth.
Beach Finding Tips
Look in the 'wrack line' or amongst rocky outcrops and tide pools at low tide. In Cancun, they are found in the thousands along rocky stretches of the Hotel Zone and Isla Mujeres.
Notes
Cancun