Star Shell (West Indian Star Snail)
Kingdom: Animalia > Phylum: Mollusca > Class: Gastropoda > Subclass: Vetigastropoda > Order: Trochida > Family: Turbinidae > Genus: Lithopoma > Species: L. phoebium · Turbinidae (Turban snails / Star shells) · Gastropod (univalve snail), complete juvenile or small specimen; star-shaped trochiform/conical.
Species
Lithopoma phoebium (formerly Astraea phoebia)
Shell Type
Gastropod (univalve snail), complete juvenile or small specimen; star-shaped trochiform/conical.
Family
Turbinidae (Turban snails / Star shells)
Size
Approximately 5–8 mm (under 0.5 inches) across, which is very small (likely a juvenile or spire view). Adult specimens typically range from 15 mm to 40 mm (0.6 to 1.5 inches) in diameter.
Color & Pattern
Off-white to light beige/pale tan with faint yellowish or grayish mottling between the radiating ribs. Exterior surface appears slightly worn/weathered with natural matte limestone-like texture.
Rarity
Common (as beach drift or live in shallow water, though small pristine juvenile specimens with intact peripheral spines require careful sorting of shell drift).
Habitat
Shallow tropical marine waters, intertidal to shallow subtidal zones down to 30 meters. Commonly found on rocks, dead coral rubble, sand flats, and seagrass beds (especially Thalassia testudinum).
Geographic Range
Tropical Western Atlantic: Florida Keys, Gulf of Mexico, Bahamas, Caribbean Sea, down to northern South America and Brazil.
Description
A small, low-conical trochiform gastropod shell viewed apical/top-down, characterized by strong radiating ribs terminating in prominent triangular star-like spines along the outer periphery of each whorl, giving the specimen a distinct star or gear shape.
Key Features
Distinctive star-shaped peripheral outline formed by flattened triangular spines/knobs along the carinated edge; low spire with pronounced radial sculpture and axial ridges.
Collector Value
Low monetary value ($1 - $5 USD), but highly valued by beachcombers and micro-shell enthusiasts for its aesthetic star shape.
Condition Notes
Fair to Good condition. Shows mild water wear and blunting of the sharp peripheral spines due to wave action, but retains clear star geometry and apical sculpture. Grade: Good (beach-found juvenile).
Interesting Facts
The living snail possesses a thick, calcareous (stony) operculum used as a protective door, which itself is often collected as a 'cat's eye' or 'mermaid's button'. They feed mainly on turf algae scraping over rocks at night.
Ecological Role
Benthic herbivore that grazes microalgae and epiphytic algae from seagrass blades and coral rubble, helping prevent algae from overgrowing coral habitats.
Similar Species
Lithopoma tectum (Imbricate Star Snail - lacks sharp star-like spines, more nodular), Lithopoma americanum (American Star Snail - taller spire, less flattened spines), Astraea heliotropium (Sunburst Carrier Shell - much larger, Pacific).
Beach Finding Tips
Look in fine shell drift lines along high tide lines in South Florida or Caribbean beaches, particularly near seagrass wash or coral reef flats after windy conditions.