Turkey Wing (also known as the Zebra Ark)
Phylum: Mollusca, Class: Bivalvia, Order: Arcida, Family: Arcidae, Genus: Arca, Species: Arca zebra · Arcidae (Ark shells) · Bivalve (Two-shelled); This specimen is a single left valve of a bivalve, characterized by an elongated, boxy shape.
Species
Arca zebra
Shell Type
Bivalve (Two-shelled); This specimen is a single left valve of a bivalve, characterized by an elongated, boxy shape.
Family
Arcidae (Ark shells)
Size
Approximately 1.5 - 2 inches long. This is a mid-sized specimen; adults typically range from 2 to 4 inches.
Color & Pattern
Shows characteristic cream-to-off-white base with reddish-brown zig-zag or 'turkey wing' banding. The pattern is somewhat faded/worn due to beach weathering (sun-bleached).
Rarity
Common; frequently found on beaches in the Caribbean and tropical Atlantic, though often as single valves rather than paired 'wings'.
Habitat
Marine; typically found attached by strong byssal threads to rocks, coral reefs, or old shells in shallow to moderately deep subtidal waters.
Geographic Range
Western Atlantic, ranging from North Carolina and Florida throughout the Caribbean (including Cancun/Mexico) to Brazil.
Description
An elongated, sturdy bivalve shell with a distinctive box-like shape. The sculpture consists of many fine radial ribs crossed by growth lines, creating a lattice-like texture. It features a wide, flat hinge area and a straight hinge line.
Key Features
Distinguished by its straight hinge line, the prominent 'beak' or umbo directed forward, and the unique 'turkey wing' color pattern. It has a notable notch for the byssus (attachment threads).
Collector Value
Low; primarily valued as a beginner's specimen or for craft work. Paired valves with intact periostracum (a fuzzy brown outer coating) are more desirable for formal collections but still widely available.
Condition Notes
Fair to Good; the specimen shows significant beach wear and erosion. The edges are smoothed by sand and surf, and the original vibrant brown pigments have faded. It is a single valve rather than a matching pair.
Interesting Facts
The name comes from the shell's resemblance to a bird's outstretched wing when both valves are opened flat. These clams attach themselves so firmly to rocks that they are difficult to remove without cutting their 'beard' (byssal threads).
Ecological Role
Suspension feeder that filters plankton from the water. It provides habitat for other organisms like bryozoans and algae that grow on its sturdy surface. Common and not currently protected.
Similar Species
Mossy Ark (Arca imbricata), which lacks the distinct zig-zag pattern and is usually more heavily encrusted or distorted in shape.
Beach Finding Tips
In Cancun, look along the high-tide line after a storm. Because they attach to reefs, they are often cast ashore when the substrate is disturbed. Look for the straight 'wing' shape among shell rubble.
Notes
Cancun