Kitten's Paw (also known as Cat's Paw)
Phylum: Mollusca, Class: Bivalvia, Order: Pectinida, Family: Plicatulidae, Genus: Plicatula, Species: Plicatula gibbosa · Plicatulidae (Kitten's Paw family) · Bivalve (two-shelled). These specimens are individual valves (single halves). The shape is fanshaped and robust with a trigonal zig-zag margin.
Species
Plicatula gibbosa
Shell Type
Bivalve (two-shelled). These specimens are individual valves (single halves). The shape is fanshaped and robust with a trigonal zig-zag margin.
Family
Plicatulidae (Kitten's Paw family)
Size
Approximately 0.5 to 0.75 inches. These are small specimens, well within the typical adult range of 0.5 to 1.5 inches for this species.
Color & Pattern
Base colors range from off-white to creamy beige with brownish or reddish-orange streaks. One specimen shows a distinct peach/orange hue. The patterns consist of small reddish-brown dots or lines following the radial ribs.
Rarity
Common. They are frequently found on the beaches of North Carolina and the Southeast US, particularly after storms or high tides.
Habitat
Subtidal marine environment. They live attached to hard substrates like rocks, corals, or other shells in shallow waters, ranging from the low tide mark to depths of about 300 feet.
Geographic Range
Western Atlantic, specifically from North Carolina (where these were found at Holden Beach) south to the West Indies and Brazil, including the Gulf of Mexico.
Description
A sturdy, thick-walled bivalve characterized by 5 to 7 prominent, heavy radial ribs. These ribs give the shell a wavy or fluted edge that resembles a kitten's paw. The exterior has a rough, somewhat scaly texture, while the interior is smooth and porcelaneous with a single muscle scar.
Key Features
Distinguished by the few, very heavy radial ribs and the interlocking, zig-zap margin where the two valves meet. The hinge lacks a long ligament line, instead featuring two small, curved teeth in each valve (isodont hinge).
Collector Value
Low monetary value ($0.50 - $1.00 each), but high sentimental value for beachcombers. They are a staple of North Carolina 'shelling' and are highly desirable for crafts and jewelry due to their durability and cute shape.
Condition Notes
Fair to Good. These specimens show some 'beach wear' (rounding of the sharpest edges due to sand tumbling), but the radial ribbing and some original color spotting remain visible. They are single valves rather than 'pairs' (joined together).
Interesting Facts
Unlike many clams that burrow in sand, Kitten's Paws cement themselves to solid objects similar to how oysters do. Their common name comes from the uncanny resemblance the closed shell has to a small cat's foot.
Ecological Role
Sessile filter feeders that help clear the water column of plankton. By attaching to hard surfaces, they contribute to the complexity of the reef or hard-bottom community. They are not currently a species of conservation concern.
Similar Species
May be confused with juvenile Atlantic Thorny Oysters (Spondylus americanus), but the Kitten's Paw has much thicker, Fewer ribs and lacks the long spines of the Spondylus.
Beach Finding Tips
Look in the 'shell hash' lines at mid-tide. They are heavy for their size, so they often settle in the same areas as small stones and thick pieces of Quahog shells. Holden Beach is an excellent location for these after a north-east wind.
Notes
Holden Beach, NC