Dwarf White Clam, Little White Clam
Phylum: Mollusca, Class: Bivalvia, Order: Venerida, Family: Veneridae, Genus: Transennella, Species: Transennella tantilla · Veneridae (Venus Clam family) · Bivalve, whole shell, fan-shaped to oval
Species
Transennella tantilla
Shell Type
Bivalve, whole shell, fan-shaped to oval
Family
Veneridae (Venus Clam family)
Size
Approximately 5 to 8 millimeters, which is typical for this diminutive species. Adults rarely exceed 10 millimeters.
Color & Pattern
Uniformly chalky white to creamy off-white exterior, sometimes with faint grayish or brownish concentric bands toward the umbo. Interior is smooth, glossy white, occasionally showing subtle purple or yellow tinges near the hinge plate.
Rarity
Common, frequently found in shell drift and sifted sand by dedicated beachcombers.
Habitat
Found in shallow intertidal and subtidal marine environments, typically buried just beneath the surface in fine sand, mud, or mixed substrates within sheltered bays and estuaries.
Geographic Range
Pacific coast of North America, ranging from Alaska down to Southern California.
Description
A tiny, sturdy bivalve with a rounded to triangular-oval shape. The exterior is finely sculpted with distinct, regular concentric ribs crossed by microscopic radial striations. The umbos are prominent and slightly prosogyrate. The ventral margin is finely crenulated, and the hinge features well-developed cardinal teeth characteristic of the Venus clam family.
Key Features
Extremely small size, robust triangular-oval profile, prominent and regular fine concentric ridging, and a finely toothed internal margin.
Collector Value
Low commercial value due to its abundance, but highly appreciated by micro-shell collectors who specialize in minute marine fauna. Typically valued at pennies per specimen.
Condition Notes
Good condition, intact whole valves with minor natural wear on the umbo. Colors are naturally bright without excessive bleaching. Collectibility grade is Good.
Interesting Facts
Unlike many bivalves that release eggs into the water column, Transennella tantilla is notable for being ovoviviparous, brooding its young internally until they reach the juvenile stage and are released as fully formed tiny clams.
Ecological Role
Serves as an important food source for small shorebirds, crabs, and carnivorous marine gastropods. Filters microscopic organic matter from the water column, contributing to coastal water clarity.
Similar Species
Other small venerid clams such as Gemma gemma (Amethyst gem clam), which tends to be more purplish and smoother near the margins.
Beach Finding Tips
Best found by using fine sand-sifting screens in sheltered tidal flats and bays along the Pacific Northwest, or by examining shell drift material under a magnifying glass.