Atlantic Kitten's Paw
Phylum: Mollusca, Class: Bivalvia, Order: Pectinida, Family: Plicatulidae, Genus: Plicatula, Species: gibbosa · Plicatulidae (Kitten's Paw family) · Bivalve (two-shelled). This specimen is a single valve (half-shell) with a fan-like, irregular triangular shape.
Species
Plicatula gibbosa
Shell Type
Bivalve (two-shelled). This specimen is a single valve (half-shell) with a fan-like, irregular triangular shape.
Family
Plicatulidae (Kitten's Paw family)
Size
Approximately 0.5 - 0.75 inches (12-19mm). This is typical for the species, which generally caps at 1 inch.
Color & Pattern
White to off-white base color with distinctive reddish-brown to maroon radiating stripes or splotches along the ridges. The pattern resembles the markings on a cat's paw.
Rarity
Very Common. These are staple finds on North Carolina beaches, especially after high tides or storms.
Habitat
Intertidal to shallow subtidal waters. They live attached to rocks, dead shells, or coral rubble on the seafloor.
Geographic Range
Western Atlantic, ranging from North Carolina south to Florida, the Gulf of Mexico, and the West Indies.
Description
A small, thick, and sturdy bivalve shell featuring 5 to 7 prominent, undulating radial ribs that give the margin a zigzag appearance. The shell is often slightly distorted because it grows attached to hard surfaces.
Key Features
Zigzag margin, heavy/thick shell for its small size, and the signature 'kitten paw' reddish-brown stripes along the ribs.
Collector Value
Low monetary value but high sentimental value for beachcombers. They are rarely sold individually and are usually collected as part of a set of local beach finds.
Condition Notes
Fair to Good. The shell shows some signs of beach wear (rounded edges and slight fading), but the diagnostic color pattern and ribbing remain clearly visible. Grade: Fine (for a beach-found specimen).
Interesting Facts
Unlike many clams that burrow in sand, Kitten's Paws are 'cemented' to hard objects like oysters or rocks during their life. They are closely related to oysters and scallops.
Ecological Role
Filter feeder that helps clear water of plankton. Their discarded shells provides a hard substrate for other small marine organisms like bryozoans or algae to grow on.
Similar Species
Juvenile Spiny Oysters (Spondylus) or small Scallops (Pectinidae). Distinguished by the Plicatula's lack of 'ears' (auricles) and its heavy, interlocking zigzag edge.
Beach Finding Tips
Look in the 'shell hash' lines at mid-tide. Because they are heavy and thick, they often settle in areas with gravel and broken shell fragments rather than fine sand.
Notes
Holden Beach, NC