Lazarus Jewel Box, Thorny Oyster (occasionally misapplied)
Kingdom: Animalia, Phylum: Mollusca, Class: Bivalvia, Order: Venerida, Family: Chamidae, Genus: Chama, Species: Chama lazarus · Chamidae (Jewel Box shells) · Bivalve (Two-shelled); specifically a cemented sessile bivalve. This is a partial specimen representing one valve with foliaceous fronds.
Species
Chama lazarus
Shell Type
Bivalve (Two-shelled); specifically a cemented sessile bivalve. This is a partial specimen representing one valve with foliaceous fronds.
Family
Chamidae (Jewel Box shells)
Size
Approximately 4-5 inches (10-13 cm). This is a large specimen for the species, as they typically average 2-4 inches.
Color & Pattern
Predominantly calcium white to creamy white. Natural specimens often show reddish-brown or purple streaks at the base of the scales, which appear faded or bleached in this specimen. The interior is generally porcelain white with possible waxy luster.
Rarity
Uncommon in this size and level of frond preservation. While the species is widespread, specimens with long, intact foliations are rarely found beachcombing as the delicate structures break easily in surf.
Habitat
Found in shallow tropical waters, typically attached to coral reefs, rocks, or other shells. They live in the subtidal zone down to approximately 30 meters.
Geographic Range
Indo-Pacific region, spanning from the Red Sea and East Africa to Polynesia and Northern Australia.
Description
A classic 'Jewel Box' shell characterized by its dramatic, leaf-like sculptural projections (foliations). The shell grows fixed to a substrate, often resulting in an irregular, distorted shape. The upper valve is heavily decorated with broad, flattened, ruff-like spines that overlap like shingles. The texture is chalky yet structurally complex.
Key Features
Distinguished by the long, broad, flattened leafy fronds rather than short spines. The hinge is 'pachydont' (thick-toothed), and the valve typically spirals slightly as it grows, resembling a distorted hoof.
Collector Value
Moderate. Well-preserved Chama lazarus with long, unbroken fronds and original pink/purple coloration can fetch $30-$75. Bleached specimens like this are valued more as decorative natural history objects or 'study' shells ($10-$20).
Condition Notes
Fair to Good. The primary foliations are mostly intact, which is desirable, but the shell shows signs of weathering and significant bleaching. There is some breakage on the delicate edges and evidence of calcified buildup at the base. Grade: Fine (for a field find).
Interesting Facts
Unlike most clams that bury themselves in sand, Jewel Boxes 'cement' themselves to the reef for life. The animal is a filter feeder. The name 'Lazarus' is a biblical reference, alluding to the way the leafy fronds look like burial shroud wrappings or a form rising from the stone.
Ecological Role
Functions as a reef-builder by adding structural complexity to the environment. They provide micro-habitats for smaller invertebrates within their fronds. They are preyed upon by specialized gastropods like Chicoreus murex and starfish.
Similar Species
Chama macerophylla (Leafy Jewel Box) found in the Atlantic, which has smaller, more crowded scales. Spondylus species (Thorny Oysters) which have more needle-like spines and a 'ball-and-socket' hinge.
Beach Finding Tips
Look in drift lines after heavy tropical storms which can dislodge them from reefs. They are often heavily encrusted with lime and algae, looking like a simple rock until cleaned with a weak acid or wire brush.