Pacific Jewel Box (also known as the Leafy Jewel Box)
Phylum: Mollusca, Class: Bivalvia, Order: Veneroida, Family: Chamidae, Genus: Chama, Species: Chama buddiana · Chamidae (Jewel Box family) · Bivalve (clams/two-shelled). It is a sessile, attached bivalve with an irregular, disc-like or cupped shape.
Species
Chama buddiana (Confidence: 85% based on location and shell morphology)
Shell Type
Bivalve (clams/two-shelled). It is a sessile, attached bivalve with an irregular, disc-like or cupped shape.
Family
Chamidae (Jewel Box family)
Size
Approximately 1 to 1.5 inches (2.5 - 4 cm) in diameter. This is a typical size for sub-adult specimens; adults can reach up to 3 inches.
Color & Pattern
Base color is a mottled tan-orange to brownish-cream. The exterior appears somewhat weathered with visible growth increments. The interior (not fully visible) is typically white with possible purple or reddish stains along the margin.
Rarity
Common in preferred habitats, though intact specimens with full 'foliaceous' (leafy) spines are often broken by surf, making well-preserved beach finds Uncommon.
Habitat
Typically found in shallow subtidal waters, cemented to hard substrates like rocks, coral reefs, or other shells. They are marine bivalves that prefer areas with high water movement.
Geographic Range
Eastern Pacific, specifically from Cabo San Lucas (Baja California, Mexico) south to Panama and occasionally Peru.
Description
This is a rugged, thick-walled bivalve characterized by its irregular shape and attachment to rocks. The exterior surface is 'foliaceous,' meaning it is covered in scale-like or leafy projections that help it blend into the surrounding reef. The valve shown appears to be the upper (right) valve, which is usually more convex and ornate than the lower valve used for attachment.
Key Features
Heavy, irregular shell; concentric growth lines with overlapping scales or spines; attachment scar on the lower valve; unequal sized valves (inequivalve).
Collector Value
Minimal monetary value for beach-worn specimens ($1-$5). Highly desired specimens are those found live with all delicate spines intact, which can be more valuable to specialized bivalve collectors.
Condition Notes
Fair condition. The shell shows significant erosion of its characteristic leafy spines, likely due to wave action or being rolled on the beach. There is evidence of calcification and possibly some minor encrusting from other organisms. Collectibility grade: Good (Beach-worn).
Interesting Facts
Jewel boxes are 'cemented' to their substrate for life, much like oysters. Because they grow to fit the contours of whatever they are attached to, no two shells are ever exactly the same shape. They are often called 'Jewel Boxes' because the interior of some species is brightly colored like a velvet-lined box.
Ecological Role
Suspension feeders that filter plankton from the water column. They provide micro-habitats for smaller invertebrates that hide within their spines and scales, and their shells contribute to reef structure.
Similar Species
Chama arcana (Secret Jewel Box) and Chama mexicana (Mexican Jewel Box). C. buddiana is distinguished by its specific geographic range in Cabo and its denser, smaller scales compared to C. mexicana.
Beach Finding Tips
Look in rocky tide pools or areas with large amounts of coral rubble after a storm. They are often overlooked because their rough texture and color make them look like common stones.
Notes
Cabo