Kitten's Paw (Commonly found as a singular lower valve fragment)
Phylum: Mollusca, Class: Bivalvia, Order: Pectinida, Family: Plicatulidae, Genus: Plicatula, Species: gibbosa · Plicatulidae (Kitten's Paw shells) · Bivalve (Two-shelled); this specimen is a heavily worn singular lower valve showing a rough, fan-like triangular shape.
Species
Plicatula gibbosa
Shell Type
Bivalve (Two-shelled); this specimen is a heavily worn singular lower valve showing a rough, fan-like triangular shape.
Family
Plicatulidae (Kitten's Paw shells)
Size
Approximately 0.75 to 1 inch. Typical adults range from 0.5 to 1.5 inches; this is a standard sized specimen.
Color & Pattern
Muted grayish-tan and dusty white. The natural reddish-brown streaks typically seen on fresh specimens have been largely sun-bleached or worn away by surf action.
Rarity
Very Common; these are frequently found in large quantities on beaches throughout the southeastern United States and the Caribbean.
Habitat
Shallow marine waters and subtidal zones; often found attached to rocks, other shells, or hard substrates on the ocean floor.
Geographic Range
Western Atlantic from North Carolina to the Gulf of Mexico, the Caribbean, and south to Brazil.
Description
A sturdy, thick-walled bivalve with a characteristic triangular or fan-like profile. This specimen shows the typical heavy ribbing that resembles the 'toes' of a small cat's paw. The exterior is naturally rough and calcified, while the interior (partially obscured) is usually smoother and pearly white.
Key Features
Heavy, undulating radial ribs (usually 5 to 7 prominent ones); thick, stony substance; asymmetrical triangular shell shape with a blunt hinge area.
Collector Value
Minimal financial value; these are primarily cherished as 'beginner' shells for hobbyists or used in shell crafts due to their abundance and durability.
Condition Notes
Poor to Fair. The shell is heavily beach-worn (tumbled), with the sharp edges of the ribs rounded off by sand and waves. No periostracum remains, and the colors are faded.
Interesting Facts
Unlike scallops that can swim, the Kitten's Paw is permanently 'cemented' to its substrate by its right valve, functioning more like an oyster in its growth habit.
Ecological Role
A filter feeder that helps clear the water of plankton; serves as a hard substrate for smaller encrusting organisms to grow upon.
Similar Species
Atlantic Thorny Oyster (juveniles) which have more distinct spines, and the Zigzag Scallop, which is larger and has more symmetrical valves.
Beach Finding Tips
Look in the 'shell hash' or drift lines after a high tide. They are heavy for their size and often settle in the mid-tide zone among crushed coral and stone.