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Saw-tooth Pen Shell

Atrina serrata

Markings and exact colorations may vary.

A big, thin, fan-shaped pen shell covered all over in tiny tube-like scales.

Typical size
6–10 in
How often it turns up
Common as fragments, uncommon whole
Collecting
Restricted

Empty shells are fine to keep on most public beaches. Live shelling is banned in Lee County and Florida state parks and needs a fishing license elsewhere — if an animal is inside, put it back.

Handling
Sharp edges

Edges and scales are brittle and sharp — pick it up by the pointed end.

How to tell it apart

  • Large triangular fan shape
  • Many fine rows of short, sharp tubular scales over the whole surface
  • Light tan to golden brown, thinner than the stiff pen shell

Where to find these in Florida

Beaches rated very good or excellent for shells. Each page shows today’s score, the best window and access details.

Found one?

Photograph it and BeachNut ranks the likely matches with a confidence read, then logs it to your collection with the beach and date.

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Commonly confused with

  • Stiff Pen ShellAtrina rigida

    Saw-tooth is covered in fine scales all over; the stiff pen shell has fewer, larger spines on stronger ribs.

  • Half-naked Pen ShellAtrina seminuda

    Half-naked is bare on its lower half; saw-tooth has scales over the whole surface.

More shells in the field guide

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