Mossy Ark
Arca imbricata (Bruguiere, 1789)
The Mossy Ark closely resembles its cousin, the Turkey Wing (Zebra Ark) in size and color but lacks the Zebra lines found in the Turkey wing. The Mossy ark has a similar brown colors on a white shell and the few brown lines run parallel to the outside edge.
Top are two joined Mossy Ark shells with two individual shells below (S. Hutchinson Island, December 2020)
Both the Mossy Ark and its closely related shell, Turkey Wing, are easily found on S. Hutchinson Island beaches.
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Mossy Ark:
Born to Shag
By Patricia B. Mitchell.
The Mossy Ark is approximately two inches long, and shaped something like a rectangular box. A fresh Mossy Ark is likely to be covered with a dark brown, moss-like covering known as the periostracum. Older, worn specimens will lack this shag. Beneath this periostracum the bivalve is purplish white. The valves have irregular growth lines, and several distinct ribs on the posterior end. One end (the anterior) of the “box” is rounded, the other end (posterior) more pointed. The two valves gape at the center. The beaks (the somewhat pointy “nose” of the shell) are far apart. The area between the beaks may be marked with geometric patterns. The edge, or margin, of the shell is smooth.
The clam attaches itself to rocks in shallow water from North Carolina to the West Indies and Brazil. It is also found on Bermuda beaches.