Button Snails, also commonly referred to as Prickly Star Snails or Toothed Star Shells
Phylum: Mollusca, Class: Gastropoda, Order: Trochida, Family: Turbinidae, Genus: Lithopoma, Species: Lithopoma caelatum · Turbinidae (Turban shell family) · Gastropod univalve, whole shells, with a turbinate to trochoid spiral shape
Species
Astraea caelata (or Lithopoma caelatum)
Shell Type
Gastropod univalve, whole shells, with a turbinate to trochoid spiral shape
Family
Turbinidae (Turban shell family)
Size
Approximately 0.5 to 1 inch in diameter, which is typical for juveniles or smaller specimens of this species; adult specimens can range up to 1.5 to 2 inches.
Color & Pattern
Mottled shades of pale green, cream, white, and subtle yellowish-brown. The colors appear slightly weathered or sun-bleached from wave action. The exterior features intricate beaded and tiled cord patterns, while the apex shows lighter cream and golden tones.
Rarity
Common to Uncommon, frequently found by dedicated beachcombers and snorkelers in the Caribbean and Florida Keys.
Habitat
Found in shallow subtidal waters, coral reefs, rocky shores, and hard limestone substrates, typically dwelling from the intertidal zone down to depths of about 30 meters. These are marine gastropods.
Geographic Range
Western Atlantic Ocean, including the Caribbean Sea, the Gulf of Mexico, southern Florida, and extending down to South America.
Description
These small, robust marine snail shells exhibit a conical or turbinate shape with a low, pointed spire. The surface is heavily ornamented with distinct sculptural rows of beads, granules, and crenulated cords that spiral around each whorl, giving them a distinctly textured and prickly appearance. The base is flattened to rounded, showcasing concentric sculpted ridges.
Key Features
Distinctive granular or beaded spiral cords encircling the whorls, a low conical profile, a sturdy calcareous structure, and a rounded, flattened base typical of the Turbinidae family.
Collector Value
Low to moderate commercial value. While widely collected as souvenirs by beachgoers, pristine specimens with bright coloration and intact opercula are more valued by regional shell collectors, typically worth a few dollars each.
Condition Notes
Good condition for beach-worn specimens. Some show minor natural erosion, small bore holes from predatory gastropods, and slight fading of the original bright green or reddish-brown hues, grading as Good to Fair collector quality.
Interesting Facts
Members of the Turbinidae family possess a heavy, calcareous operculum (trapdoor) that seals the aperture when the animal retreats inside. Historically and culturally, these opercula have been used as jewelry or charms, often referred to as 'cat's eyes'.
Ecological Role
As herbivorous grazers, these snails play an important role in marine ecosystems by feeding on microalgae and macroalgae, helping to control algae growth on coral reefs. They serve as prey for various carnivorous fish, larger gastropods, and crustaceans.
Similar Species
Other members of the Lithopoma genus, such as Lithopoma americanum (the American Star Shell) and Lithopoma tuber (the Green Star Shell), which can be distinguished by differences in spine prominence, cord spacing, and overall coloration.
Beach Finding Tips
Look along Caribbean and South Florida beaches near rocky outcroppings, coral rubble zones, or driftlines after storms at low tide. Sifting through shell gravel and tide pools often yields smaller specimens.