False smooth snake

Description

The fan mussel,Atrina fragilis,is a species of large saltwater clam,a marine bivalve mollusc in the family Pinnidae,the pen shells.The fan mussel is one of the largest (30 to 48 cm long) European bivalve molluscs.It is one of the rarest species of marine mollusc in the United Kingdom - so rare that surveys of nearly 9,000 sites around Britain between 1987 and 1998 found noneThe shell of the fan mussel tapers to a point at the umbos,and is very brittle.It is yellowish to dark brown with blackish patches.The two valves are equal and triangular in outline,with prominent gapes.The shell surface has a sculpture of concentric lines and 8 to 12 ribs,which may have fluted spines.Shells can reach 48 cm in length,and the largest individuals may be 10 to 12 years old.Also have been found in the Mediterranean Sea