Tegula Shell, also known as Top Snail
Phylum: Mollusca, Class: Gastropoda, Order: Trochida, Family: Trochidae, Genus: Tegula, Species: Tegula funebralis · Trochidae (Top Snail family) · Gastropod (snail/univalve), whole shell, conical shape
Species
Tegula funebralis (Black Turban Snail)
Shell Type
Gastropod (snail/univalve), whole shell, conical shape
Family
Trochidae (Top Snail family)
Size
Approximately 1 to 1.5 inches in width, which is average for an adult of this species. Typically, adults range from 0.75 to 1.25 inches.
Color & Pattern
Dark purplish-black to greenish-brown base color, often showing lighter whitish or yellowish erosion marks near the apex. The surface features faint spiral cords and growth lines.
Rarity
Common, frequently found along rocky shores within its native range.
Habitat
Intertidal and shallow subtidal zones, typically found on rocky shores, tide pools, and areas with strong wave action attached to rocks or algae.
Geographic Range
Northeastern Pacific Ocean, ranging from British Columbia, Canada down to central Baja California, Mexico.
Description
A sturdy, compact conical shell with a low-spired profile and rounded whorls. The surface has subtle spiral ridges and a dark, weathered dark purple-brown exterior. The aperture is rounded and smooth, often silvery or pearly inside.
Key Features
Conical shape, low spire, dark purplish-black coloration, rounded whorls, and a pearly interior nacre visible near the aperture.
Collector Value
Low to moderate commercial value; commonly collected as a representative rocky-shore gastropod rather than a high-end collector piece, usually worth a few dollars.
Condition Notes
Fair to Good condition; shows some natural wear and bleaching near the apex typical of intertidal exposure, but the overall structure remains intact.
Interesting Facts
Black turban snails are known to flip themselves over using their muscular foot when dislodged by waves or predators like seastars. They graze primarily on microalgae and kelp.
Ecological Role
Acts as an important herbivore controlling algal growth on rocky shores and serves as prey for sea stars, crabs, and predatory snails.
Similar Species
Chlorostoma brunnea (Brown Turban) which is browner and lacks the deep purple-black hue, and Lirabuccinum dirum which is elongated.
Beach Finding Tips
Look along rocky intertidal zones, tide pools, and drift lines on pebble or rocky beaches on the Pacific coast, particularly during low tide.