Kitten's Paw (also known as the Plicate Oyster)
Phylum: Mollusca, Class: Bivalvia, Order: Pectinida, Family: Plicatulidae, Genus: Plicatula, Species: P. gibbosa · Plicatulidae (Kitten's Paw family) · Bivalve; this specimen is a single valve (one half of the shell). The shape is irregularly fan-like or trigonal, resembling a feline's foot.
Species
Plicatula gibbosa
Shell Type
Bivalve; this specimen is a single valve (one half of the shell). The shape is irregularly fan-like or trigonal, resembling a feline's foot.
Family
Plicatulidae (Kitten's Paw family)
Size
Approximately 0.75 to 1 inch (20-25mm). This is typical for the species, which rarely exceeds 1.5 inches.
Color & Pattern
Base color is a creamy white to pale orange, featuring 5-7 prominent radial ribs often marked with reddish-brown or orange streaks. The specimen appears somewhat weathered with some natural bleaching.
Rarity
Very Common; ubiquitous on beaches in Florida and the Caribbean after storms or high tides.
Habitat
Marine; found in shallow subtidal waters attached to hard substrates like rocks, dead shells, or coral rubble. Often found in high-energy surf zones.
Geographic Range
Western Atlantic, ranging from North Carolina south through the Gulf of Mexico, Caribbean, and Brazil.
Description
A thick, sturdy, and heavy bivalve for its size. The shell features several deep, undulating radial ribs that create a zig-zag interlocking margin where the two valves meet. The exterior is rugose and often encrusted, while the interior is smooth and white.
Key Features
The distinctive 'paw' shape with deep longitudinal folds and a very thick, porcelain-like texture. It lacks the 'ears' (auricles) found on scallops.
Collector Value
Minimal monetary value ($1-$2) but high aesthetic 'charm' value for beachcombers. Pristine 'double' specimens (both valves attached) are more desirable to serious collectors.
Condition Notes
Fair condition. It is a single beach-worn valve with significant erosion on the dorsal surface, likely showing some calcification or sponge boring. The orange pigmentation remains visible.
Interesting Facts
The name 'Kitten's Paw' comes from the internal margin and ribs which, when viewed together, look like the toes of a cat. Unlike scallops, they are sessile and cement themselves to objects.
Ecological Role
Suspension feeder that filters plankton from the water column. Provides micro-habitats for smaller encrusting organisms on its thick, ridged surface.
Similar Species
Juvenile Lion's Paw (Nodipecten nodosus) which has 'ears' at the hinge, and various species of Ostreidae (Oysters), though Kitten's Paws are much heavier and more symmetrical.
Beach Finding Tips
Look in the 'shell hash' or drift line after a storm. Their weight causes them to settle in pockets with other heavy objects like stones and thick clamshells.