Pacific Surf Clam (Venus Clam)
Phylum: Mollusca, Class: Bivalvia, Order: Venerida, Family: Veneridae, Genus: Tivela, Species: Tivela stultorum · Veneridae (Venus Clams) · Bivalve (Single Valve). Shape: Triangular-ovate, heavy and solid.
Species
Tivela stultorum
Shell Type
Bivalve (Single Valve). Shape: Triangular-ovate, heavy and solid.
Family
Veneridae (Venus Clams)
Size
Approximately 2.5-3 inches across. This is a juvenile to sub-adult size, as they can grow up to 7 inches.
Color & Pattern
Pale cream to yellowish-tan base with faint radiating brown rays or bands. The surface is smooth and glossy, with visible concentric growth lines and a slight waxy sheen.
Rarity
Common to Very Common. Frequently found on sandy beaches after storms or high tides in Baja.
Habitat
Intertidal to shallow subtidal zones, typically found in sandy beaches with heavy surf where it burrows deeply (up to 1 foot) into the sand.
Geographic Range
Eastern Pacific Ocean, ranging from Northern California down to Baja California (Mexico), common in the Cabo San Lucas region.
Description
A thick, heavy, and remarkably smooth bivalve valve. The shell is wedge-shaped with a prominent beak (umbo) positioned near the center. The exterior is highly polished in life, though beach-worn specimens can become matte. It features subtle radial banding that suggests the 'sunray' pattern typical of the genus.
Key Features
Equilateral triangular shape, thick heavy shell wall, smooth polished surface, and characteristic radiating color bands moving from the umbo to the margin.
Collector Value
Low. These are widely available and popular for craft use or as souvenirs, though exceptionally large, paired 'gem' specimens (both valves joined) hold more interest for serious collectors.
Condition Notes
Good condition. The shell appears to be a beach-found single valve with some light water-wear on the edges. The color is well-preserved, showing the natural rays clearly.
Interesting Facts
Despite its name 'stultorum' (meaning 'of the fools'), it is highly adapted to the surf. In California, these were historically so abundant that they were harvested by horse-drawn plows for food. They can live up to 50 years.
Ecological Role
A significant filter feeder that helps clear particulates from shore waters. It is a primary food source for sea otters, rays, and larger carnivorous snails like whelks.
Similar Species
Tivela hians (more elongated) and Megapitaria squalida (Chocolate Clam), which is much darker brown and lacks the distinctive triangular wedge shape.
Beach Finding Tips
Search sandy beaches at low tide, especially after heavy Pacific surf. Look for the polished, yellowish curve of the shell poking through the sand near the water's edge.
Notes
Cabo