Pacific Jewel Box (or Leafy Jewel Box)
Phylum: Mollusca, Class: Bivalvia, Order: Veneroida, Family: Chamidae, Genus: Chama, Species: Chama buddiana · Chamidae (Jewel Box family) · Bivalve (Two-shelled); this specimen is a single valve (likely the upper/free valve). Shape is irregularly circular and globose.
Species
Chama buddiana (Confidence: 85% based on location and morphology)
Shell Type
Bivalve (Two-shelled); this specimen is a single valve (likely the upper/free valve). Shape is irregularly circular and globose.
Family
Chamidae (Jewel Box family)
Size
Approximately 1.5 inches (3.8 cm) in diameter. Typical range for this species is 1 to 3 inches.
Color & Pattern
Naturally creamy white to pale grey with faint yellowish or tan concentric banding. The specimen appears significantly water-worn and sun-bleached, which has muted the original reddish-purple highlights often found near the attachments.
Rarity
Common; frequently found as beach-worn valves on Pacific coastlines of Mexico.
Habitat
Found in shallow marine environments, intertidal to sub-tidal depths. Typically attached to rocks, coral, or other shells on sandy or rocky substrates.
Geographic Range
Eastern Pacific, specifically from the Gulf of California (Cabo San Lucas) south to Peru.
Description
A robust, thick-walled bivalve characterized by its cement-like attachment to hard surfaces. While live specimens feature flared, leafy proccesses (foliations), this beach-found valve is smoothed by wave action, exhibiting a chalky texture and visible growth lines.
Key Features
Heavy, porcelain-like weight for its size; irregular shape due to its sessile (attached) lifestyle; a thickened, often denticulated inner margin; and a strongly curved umbo (beak).
Collector Value
Minimal financial value ($1-$5) due to its worn condition, but holds high sentimental value as a representative specimen of the Panamic structural fauna.
Condition Notes
Fair condition for a beach find. Significant erosion has smoothed the typical 'leafy' spines of the Jewel Box family. No obvious predator drill holes, but it lacks the vibrant interior coloration of a live-taken specimen.
Interesting Facts
Jewel boxes are 'cemented' bivalves; they choose a rock or another shell early in life and grow their bottom shell to match the contour of that surface perfectly. They are often overlooked because they camouflage with the reef.
Ecological Role
Secondary reef builders; they provide hard substrate for other organisms to grow on. They are filter feeders that help maintain water clarity by consuming plankton.
Similar Species
Chama hispida and Chama arcana. Distinguishable by the direction of the shell's spiral (left vs right attachment) and the specific texture of the exterior spines.
Beach Finding Tips
Look near rocky outcrops and tide pools in Cabo after high tide. Because they are heavy, they often settle in the 'shell hash' lines rather than the fine sand.
Notes
Cabo