Antillean Slipper Limpet (also known as the Antillean Slipper Shell)
Phylum: Mollusca, Class: Gastropoda, Order: Littorinimorpha, Family: Calyptraeidae, Genus: Crepidula, Species: Crepidula antillarum · Calyptraeidae (Slipper snails and cup-and-saucer limpets) · Gastropod (univalve) whole shell, cap-shaped or slipper-shaped with an internal deck
Species
Crepidula antillarum
Shell Type
Gastropod (univalve) whole shell, cap-shaped or slipper-shaped with an internal deck
Family
Calyptraeidae (Slipper snails and cup-and-saucer limpets)
Size
Approximately 0.5 inches (12-15 mm) in length, which is typical for this species. Adults generally range from 0.4 to 0.8 inches.
Color & Pattern
The exterior features a whitish or pale cream base color adorned with distinctive reddish-brown or chestnut spots, streaks, and irregular blotches radiating or patchy along the margin. The interior showcases a glossy white surface with a prominent, white internal shelf (the septum or deck) covering the posterior half of the aperture.
Rarity
Common, frequently discovered by beachcombers who search through shell drift or inspect the surfaces of larger discarded gastropod shells.
Habitat
Inhabits marine shallow subtidal to intertidal zones, often attaching itself to hard substrates such as rocks, shells of other mollusks, and dead coral fragments in protected tropical waters.
Geographic Range
Widespread throughout the tropical Western Atlantic, including the Caribbean Sea, the Gulf of Mexico, Florida, and south along the coast of South America, consistent with the reported origin of Antigua.
Description
A charming and compact slipper snail characterized by its ovate, cap-like form and arched profile. The apex is small and slightly curved toward the posterior margin. The defining feature is the delicate, porcelain-white internal deck that spans half of the interior cavity, providing structural support and protection for the animal's visceral mass. The exterior exhibits smooth growth lines interrupted by striking dark brown markings over a pale background.
Key Features
Distinguished by its small, cap-like slipper shape, the presence of a distinct internal half-deck (septum), and the characteristic reddish-brown blotches and streaks over a whitish background.
Collector Value
Low to moderate commercial value as an individual specimen, but highly valued by regional Caribbean shell collectors and micro-mollusk enthusiasts for completeness and locality data. Typically valued at a few dollars.
Condition Notes
The specimen appears to be in Good to Fine condition, largely intact with clear color patterns visible, minor natural wear around the margins, and an unbroken internal deck.
Interesting Facts
Like many slipper limpets, Crepidula species are sequential hermaphrodites, starting life as males and later transforming into females. They often stack on top of one another in breeding chains, where the larger female sits at the bottom and smaller males attach to her shell.
Ecological Role
Acts as a suspension feeder, filtering microscopic plankton and organic particles from the water column. They form an important part of the benthic food web, serving as prey for carnivorous snails, crabs, and fish.
Similar Species
Crepidula plana (Eastern White Slipper Shell), which is typically pure white and flatter, and Crepidula fornicata (Common Slipper Shell), which is larger and more deeply arched with brownish mottled patterns.
Beach Finding Tips
Look along high-tide shell lines, sift through fine shell drift, and inspect the interior of larger empty gastropod shells where these small limpets frequently anchor themselves.
Notes
Antigua