The Smooth Duck Clam, Anatina anatina (Spengler, 1802), is a bivalve rarely found in Southwest Florida. It is a close relative of the more common Channeled Duck Clam, Raeta plicatella (Lamarck, 1818), with which it could be confused. Both have very thin, fragile shells, but the latter species, however, shows a sculpture of broader concentric ribs and more rounded outline. The Smooth Duck Clam, as other species of the family Mactridae, has its two long siphons (one sucks water in for filter-feeding, the other expels the used water) fused to form a single, elephant trunk-like structure. This is shown in the Amy Tripp’s illustration of the live clam (the photo was taken in Collier County). The photo also shows the clam’s digging foot on the right.
The Smooth Duck Clam, shell and live animal. The live animal image shows the fused siphons on the left and the clam’s foot on the right. Photo of the live animal by Amy Tripp in Collier County.