Atlantic Kitten's Paw
Phylum: Mollusca, Class: Bivalvia, Order: Pectinida, Family: Plicatulidae, Genus: Plicatula, Species: gibbosa · Plicatulidae (Kitten's Paw family) · Bivalve (clams/two-shelled); this specimen is a single valve with a fan/paw shape.
Species
Plicatula gibbosa
Shell Type
Bivalve (clams/two-shelled); this specimen is a single valve with a fan/paw shape.
Family
Plicatulidae (Kitten's Paw family)
Size
Approximately 0.75 - 1 inch. This is a very common size for the species, which typically matures at 0.5 to 1.5 inches.
Color & Pattern
Base color is a warm reddish-brown to orange-tan. It features distinct radial ribs that are darker than the valleys. The color appears natural and well-saturated, though slightly worn at the hinge (umbo) which reveals a lighter, creamy underlayer.
Rarity
Very Common. These are frequently found on North Carolina beaches, especially after storms or heavy surf.
Habitat
Intertidal to shallow subtidal waters. Often found attached to rocks, coral, or other shells. It lives in marine environments along coastal shores.
Geographic Range
Western Atlantic from North Carolina (including Holden Beach) south to Brazil, including the Gulf of Mexico and the Caribbean.
Description
Strong, thick, and heavy for its size, this small bivalve resembles a feline's foot. It features 5 to 7 prominent, coarse, undulating radial ribs that create a zig-zag margin where the two valves meet. The texture is rough and scaly.
Key Features
Distinctive 'kitten paw' shape, thick shell wall, and the presence of heavy, wavy radial ribs. The interior (not visible) typically has small 'teeth' along the margin.
Collector Value
Low monetary value due to high abundance, but high sentimental value for beachcombers. Exceptional specimens with both valves still attached are more desirable to serious collectors.
Condition Notes
Good. The shell shows some minor beach-wear on the rib peaks and the hinge, but the color is vibrant and the structure is intact. Collectibility grade: Fine.
Interesting Facts
Unlike many clams that burrow, the Kitten's Paw cements itself to hard surfaces like a tiny oyster. They are often used in shell crafts and jewelry due to their durability and cute, symbolic shape.
Ecological Role
Filter feeders that help clear the water of plankton and organic detritus. They serve as a food source for sea stars and snails like the murex. Not currently a species of conservation concern.
Similar Species
Juvenile Giant Atlantic Cockles (Dinocardium robustum) have more numerous, finer ribs. Juvenile Scallops (Pectinidae) have distinct auricles (ears) at the hinge which Plicatulidae lack.
Beach Finding Tips
Search for them in the shell hash near the high tide line or in the wash zone. Their weight causes them to settle with larger shell fragments. Look for the distinct reddish-orange 'paw' shape among white shell pieces.
Notes
Holden Beach, NC