Common Jingle Shell, Mermaid's Toenail, Saddle Oyster
Phylum: Mollusca, Class: Bivalvia, Order: Pectinida, Family: Anomiidae, Genus: Anomia, Species: simplex · Anomiidae (Jingle shells) · Bivalve (upper valve); characteristic thin, translucent, bowl-like shape.
Species
Anomia simplex
Shell Type
Bivalve (upper valve); characteristic thin, translucent, bowl-like shape.
Family
Anomiidae (Jingle shells)
Size
Approximately 1 inch (2.5 cm) in diameter. This is a standard size for a mature adult, though they can reach up to 2 inches.
Color & Pattern
Silvery-gray to iridescent blue-gray interior with a pearly luster. The exterior is naturally translucent with subtle concentric growth rings. This specimen shows some typical beach-worn dullness but retains its distinctive central muscle scar pattern.
Rarity
Very Common
Habitat
Found in shallow coastal waters, estuaries, and bays. They live attached to hard substrates like rocks, larger shells (especially oysters), or submerged pilings.
Geographic Range
Western Atlantic, ranging from Southern Massachusetts and New York down to Brazil; very common along the Gulf of Mexico and Caribbean coastlines.
Description
A delicate, paper-thin bivalve shell with an irregular, wavy margin. This is the upper (left) valve, which is convex and lacks the hole found in the lower valve. It has a beautiful translucent, nacreous (pearly) interior that creates a distinctive 'jingle' sound when several are shaken together.
Key Features
Translucent property; iridescent luster; lack of hinge teeth; presence of three distinct muscle scars on the interior of the upper valve (one large, two small).
Collector Value
Low monetary value due to extreme abundance. They are highly desired by crafters for making wind chimes, jewelry, and 'mermaids toenail' folk art collections.
Condition Notes
Fair to Good. The shell is largely intact but shows chipped edges and some surface erosion (chalkiness) typical of beach-drifted specimens. The iridescence is still visible in the center.
Interesting Facts
The 'jingle' name comes from the sound they make in a collector's pocket. The animal attaches to surfaces via a calcified byssus (a group of threads) that passes through a permanent hole in the bottom valve, essentially molding the shell to the shape of the rock it sits on.
Ecological Role
Suspension feeders that filter plankton from the water column. They provide minor structural complexity to reefs and are preyed upon by sea stars and certain gastropods.
Similar Species
Pododesmus rudis (False Jingle Shell) which is thicker, less translucent, and has only two muscle scars instead of three.
Beach Finding Tips
Look along the high-tide line after a storm. They are often found mixed in with shell hash or clinging to old oyster clumps. They are most easily spotted by their pearly glint against the sand.