Stiff Penshell

Stiff Penshell

This photo clearly shows the old quill pen shape that gives the Stiff Penshell its name, usually hidden because the shell is stuck in sand or coral.

Name: Stiff Penshell
Scientific Name: Atrina rigida
Family: Pen Shells
Taxonomic: Pinnidae
ID Group: Snails, Clams & Shells
Size: up to 11 in.
Depth Range: On the reef (10 – 60 ft.)
Sightings: Seen sometimes

This fan-shaped Pen Shell has 25 raised ribs with tube-like spines. Its color ranges from dark to light brown.

The Stiff Penshell partly buries itself with its narrow tip hidden in sand or coral crevices.