Top Snail / Top Shell (Sculptured Top Shell)
Phylum: Mollusca - Class: Gastropoda - Subclass: Vetigastropoda - Order: Trochida - Superfamily: Trochoidea - Family: Calliostomatidae - Genus: Calliostoma - Species: Calliostoma euglyptum · Calliostomatidae (Top Shell family / Calliostoma snails) · Gastropod (univalve snail), conical top-shaped (trochiform) whole shell.
Species
Calliostoma euglyptum (Likely, 85% confidence based on conical geometry and beaded spiral cords)
Shell Type
Gastropod (univalve snail), conical top-shaped (trochiform) whole shell.
Family
Calliostomatidae (Top Shell family / Calliostoma snails)
Size
Approximately 5 mm to 8 mm in height and width. This is a small juvenile specimen; fully adult specimens typically reach 15-25 mm.
Color & Pattern
Off-white to pale cream base with subtle brownish spots along the beaded ridges. The interior of the aperture displays a faint nacreous (mother-of-pearl) iridescence typical of trochids.
Rarity
Uncommon as a whole beach find due to its delicate size and juvenile nature, though fairly common in offshore dredgings.
Habitat
Subtidal marine environments, shallow water to moderate depths (5-50 meters) on hard substrates, rocky bottoms, or attached to hydroids and sponges.
Geographic Range
Western Atlantic, ranging from North Carolina south through Florida, the Gulf of Mexico, and into the Caribbean.
Description
A miniature, perfectly trochiform (top-shaped) gastropod shell featuring straight, sharply conical whorls decorated with raised, beaded spiral cords (granulated ribs). The base is flat with an angled periphery and a wide, open aperture showing iridescent nacre inside.
Key Features
Strictly conical profile with straight sides, beaded/granulated spiral ridges, absence of a true umbilicus in adult forms, and nacreous inner lining.
Collector Value
Low monetary value ($1 - $5) due to small size and beach-worn state, but high aesthetic interest for micro-shell collectors.
Condition Notes
Fair to Good condition for a micro-shell. Shows light beach wear along the outer lip, slightly faded coloration, but intact apex and distinctive sculpture.
Interesting Facts
Calliostoma snails are known to feed on cnidarians such as hydroids and anemones, as well as sponges, incorporating toxins from their prey for defense.
Ecological Role
Benthic predator/epifaunal browser, grazing on micro-algae, encrusting bryozoans, and colonial hydroids on hard substrate structures.
Similar Species
Calliostoma jujubinum (Jujube Top Shell, which has slightly more inflated whorls and darker brownish-red streaks) and Tegula species (which are generally rounder and darker).
Beach Finding Tips
Sift through fine shell hash at the high tide line or examine drift lines near rocky inlets using a magnifying glass or sieve.