Atlantic Jingle Shell, Mermaid's Toenail, Baby's Footprint
Phylum: Mollusca, Class: Bivalvia, Order: Pectinida, Family: Anomiidae, Genus: Anomia, Species: Anomia simplex · Anomiidae (Jingle shells) · Bivalve (Two-shelled); though usually found as a single valve. Shape: Irregular, translucent, somewhat circular to pear-shaped.
Species
Anomia simplex
Shell Type
Bivalve (Two-shelled); though usually found as a single valve. Shape: Irregular, translucent, somewhat circular to pear-shaped.
Family
Anomiidae (Jingle shells)
Size
Approximately 1 inch (25mm) in diameter. This is a very common size for an adult specimen of this species, which typically ranges from 0.5 to 2 inches.
Color & Pattern
Deep amber-orange with a lustrous, pearly sheen. The shell exhibits natural translucency. No distinct banding is present, but it shows subtle concentric growth lines and a silvery iridescence on the interior.
Rarity
Very Common. These are some of the most frequently found shells on Holden Beach, particularly after high tides or storms.
Habitat
Coastal marine environments; typically found attached to hard substrates like rocks, oyster reefs, boat hulls, or other shells. Found from the intertidal zone to depths of 30 feet.
Geographic Range
Western Atlantic, ranging from Southern Massachusetts down to Brazil, including the Gulf of Mexico and the Caribbean. Very common along the North Carolina coast.
Description
An attractive, thin, and translucent bivalve shell with a characteristic 'mother-of-pearl' luster. The upper (left) valve is convex and often takes on the shape of the object it was attached to, while the lower (right) valve is flat and contains a small hole (foramen) for the byssal plug. This specimen is an upper valve, featuring a smooth but slightly wavy texture and a warm orange glow.
Key Features
Translucent appearance, pearly or satiny luster, and thin, brittle structure. The internal muscle scars (not fully visible here) and the absence of a hinge teeth help distinguish it from other small bivalves.
Collector Value
Minimal monetary value (typically less than $1) due to abundance, but highly desired by beachcombers and crafters for jewelry and wind chimes. Deeper colors like bright orange or black are more prized than common translucent white.
Condition Notes
Good condition. The shell has retained its vibrant orange pigment and lustrous finish. There is minor chipping along the delicate margins, which is typical for beach-worn specimens. Overall grade: Fine.
Interesting Facts
They are called 'Jingle Shells' because a handful of them in a pocket or jar makes a metallic jingling sound. The living animal attaches itself to rocks via a calcified byssus that passes through a hole in the bottom shell, making it virtually immovable.
Ecological Role
Filter feeder that consumes plankton and organic detritus, helping to clear the water columns. They serve as a food source for starfish and drum fish. They are common members of the fouling community on artificial structures.
Similar Species
Anomia ephippium (European Jingle), which is found in the Eastern Atlantic. It can also be confused with the False Jingle (Pododesmus rudis), which is thicker and less translucent.
Beach Finding Tips
Look in the 'shell hash' lines at mid-tide or among oyster clumps. At Holden Beach, they are most abundant after a strong offshore wind or storm has churned up the subtidal zone.
Notes
Holden Beach, NC