The Pinnidae are a taxonomic family of large saltwater clams sometimes known as pen shells. They are marine bivalve molluscs in the order Pteriida.

Pen shells are found throughout Florida waters and are often observed washed up on local beaches after periods of high winds and wave action. The adductor muscle inside the pen …

May 24, 2011 · The stiff pen shell, or rigid pen shell, is one of the several species of pen shells. These mollusks have a long, triangular, or wedge-shaped shell and attach to rocks or shells in …

M-650 PEN SHELL, Atrina rigida, or A. serrata. A large, brown fan-shaped bivalve that anchors itself down into the sand with an enormous tuft of silk byssus threads. Historians suggest that …

Pinna nobilis, known by the common names noble pen shell and fan mussel, is a large species of Mediterranean clam, a marine bivalve mollusc in the family Pinnidae, the pen shells. [2] It …

Pinna carnea, commonly called the amber pen shell, is a species of bivalve mollusc in the family Pinnidae. The amber pen shell has a pair of long, thin translucent valves held together by …

bivalve, (class Bivalvia), any of more than 15,000 species of clams, oysters, mussels, scallops, and other members of the phylum Mollusca characterized by a shell that is divided from front …

Pinnidae, the pen shells, have thin, fan-shaped, translucent shells. The outer shell may have radial ribs and or small scales or spines. The inside has a shiny, iridescent part called the …

Pen Shells can be very large, and up to 95 cm (37 inches) in length. They are preyed upon by shorebirds, crabs, carnivorous mollusks and fish. They are found in shallow water in tropical …

The Sawtooth Pen Shell is 8 to 12 inches long. Its fragile, translucent valves are yellowish-brown on the exterior. The inside surface of the bivalve halves is a lovely, iridescent, peacock-like …