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 (two-shelled). The specimen shown is a single valve (either left or right) with a fan-like, cat's paw shape.
Species
Plicatula gibbosa (Confidence: 95%)
Shell Type
Bivalve (two-shelled). The specimen shown is a single valve (either left or right) with a fan-like, cat's paw shape.
Family
Plicatulidae (Kitten's Paw family)
Size
Approximately 12-15mm (0.5 inches) in diameter. This is a small/juvenile specimen; adults typically reach 20-30mm (1 inch).
Color & Pattern
Base color of creamy white with prominent, radiating reddish-brown or orange-brown streaks localized on the peaks of the ribs. The colors appear natural but slightly worn from surf action. The interior (not fully visible) is typically white with a single muscle scar.
Rarity
Common. They are frequently found washed up on beaches in the Caribbean and Florida, though their small size makes them easy to overlook in the shell hash.
Habitat
Found in shallow marine waters, typically attached to rocks, dead shells, or coral rubble by the right valve. They prefer tropical to subtropical environments.
Geographic Range
Western Atlantic, from North Carolina through the Gulf of Mexico, the Caribbean (including Cancun/Yucatan), and south to Brazil.
Description
A thick, heavy, and very sturdy little bivalve shell. It features 5 to 8 sharp, radiating plications (folds or ribs) that give the edge a zig-zag or scalloped appearance. The shell's resemblance to a cat's paw is the source of its charming common name.
Key Features
The most distinguishing features are the thick, heavy shell wall relative to its small size and the distinct 'plications' or folds that create a jagged margin. Unlike scallops, they lack 'ears' (auricles) at the hinge.
Collector Value
Low monetary value ($0.50–$2.00), but high aesthetic 'charm' value. They are a staple of casual beachcomber collections and are often used in shell art and jewelry due to their sturdiness and cute shape.
Condition Notes
Fair to Good. The shell shows some signs of beach wear (rounded edges on the ribs) and minor erosion near the umbo (beak). The coloration is still quite vivid, which is desirable for beach-found specimens. Collectibility Grade: Fine (standard beach specimen).
Interesting Facts
The 'Kitten's Paw' is a sessile animal, meaning it cements one side of its shell permanently to a hard surface. Because they are so thick-walled, these shells are extremely durable and can survive in the surf zone much longer than more delicate shells.
Ecological Role
They are filter feeders, helping to clear the water of plankton and organic particles. They serve as a food source for specialized predatory snails and crabs that can crush or drill through their thick shells.
Similar Species
Can be confused with juvenile Spondylus (Thorny Oysters) or small Nodipecten (Lion's Paws). However, the Plicatula lacks spines and the characteristic hinge 'ears' of the scallop family.
Beach Finding Tips
Look in the shell drift lines after a high tide, specifically in areas with coral rubble. In Cancun, they are often found among the small stones and broken shell fragments near the water's edge.
Notes
Cancun