Smooth Brown Venus, Glossy Venus, or Portuguese Clam
Phylum: Mollusca, Class: Bivalvia, Order: Venerida, Family: Veneridae, Genus: Callista, Species: Callista chione · Veneridae (Venus Clams) · Bivalve (Two-shelled); Fan-shaped/Oval; Single valve (half-shell) present in image
Species
Callista chione
Shell Type
Bivalve (Two-shelled); Fan-shaped/Oval; Single valve (half-shell) present in image
Family
Veneridae (Venus Clams)
Size
Approximately 7-8 cm (2.7-3.1 inches). This is a mature specimen; the species typically reaches max sizes of 9-10 cm.
Color & Pattern
Glossy cream to light tan base with distinctive concentric reddish-brown bands and radiating streaks. The surface exhibits a naturally high-gloss finish as if lacquered. The interior is generally porcelain-white and smooth.
Rarity
Common (frequently found washed up on Portuguese beaches after storms or high tides).
Habitat
Inhabits sandy substrates in clean, open coastal waters. Found from the low-tide mark down to depths of 180 meters, preferring shallow subtidal zones.
Geographic Range
Common throughout the Mediterranean Sea and the Atlantic coast from the British Isles down to Morocco and the Canary Islands; very prevalent along the Algarve coast of Portugal.
Description
A robust, thick-walled bivalve known for its elegant oval-oblong shape and remarkably smooth, shiny exterior. The shell is heavy for its size, indicating its strength. It features fine concentric growth lines and a prominent umbo (beak) curved slightly toward the front.
Key Features
High-gloss porcelaneous finish; reddish-brown radiating bands; thick, heavy valves; smooth margins (no teeth-like serrations on the edge); non-pallial sinus typically visible on the interior.
Collector Value
Modest ($2-$10 USD). While common, it is highly desired for its aesthetic gloss and 'perfect' appearance. Specially colored or exceptionally large specimens are more sought after.
Condition Notes
Good to Fine. The specimen shows natural coloration and its signature gloss, though some slight dulling at the umbo suggests minor sand abrasion. No predatory drill holes are visible.
Interesting Facts
In Portugal and Spain, this clam is known as 'Amêijoa-macha' or 'Concha Fina' and is a prized culinary delicacy. The animal is long-lived, with some specimens reaching over 40 years of age.
Ecological Role
Suspension feeder that filters plankton from the water column. It serves as a vital food source for sea stars, gastropods (like Murex), and rays. Currently has no major conservation concerns but is commercially harvested.
Similar Species
Macrocallista nimbosa (Sunray Venus) found in the Americas; Callista chione is distinguished by its shorter, more rounded oval shape and Mediterranean/East Atlantic range.
Beach Finding Tips
In Carvoeiro, search the drift line after a period of rough surf or strong Atlantic swells. They are most often found as single valves, but paired 'butterfly' shells can be found by wading in shallow water at low tide.
Notes
In portugal in carvoeiro It is very strong and it’s sides are wide