Common Slipper Limpet

The size of the shell is 20–50 mm. The maximum recorded shell length is 56 mm.

This sea snail has an arched, rounded shell. On the inside of the shell there is a white "deck", which causes the shell to resemble a boat or a slipper, hence the common names. There is variability in the shape of the shell: some shells are more arched than others.

Groups of individuals are often found heaped up and fastened together, with the larger, older females below and the smaller, younger males on top. As a heap grows, the males turn into females (making them sequential hermaphrodites).

The species is native to the western Atlantic Ocean, specifically the Eastern coast of North America. Its distribution ranges from 48°N to 25°N; 97.2°W to 25°W from as far north as Nova Scotia to as far south as the Gulf of Mexico. It has been introduced accidentally to other parts of the world and has become problematic.

Generally for Calyptraeidae, feeding habits include planktonic and minute detrital food items through either suspension or deposit feeding.

Although Crepidula fornicata is a species with cosmopolitan distribution, and can tolerate a wide range of environmental conditions, populations are particularly well developed in wave protected areas such as bays, estuaries or sheltered sides of wave exposed islands. Their distribution within the water column has been shown to a minimum of 0m and a maximum of 70m. They are often found living stacked on top of one another on rocks, on horseshoe crabs, shells and on dock pilings.

The species is a sequential hermaphrodite. The slipper limpet normally lives in stacks of up to 12 individuals, with the largest at the bottom and with increasingly smaller individuals stacked on top of one another. The largest and oldest animals, at the base of a pile are female, the younger and smaller animals at the top are male. If the females in the stack die, the largest of the males will become a female. Breeding can occur between February and October with peak activity occurring in May and June. Roughly 80-90% of females spawn during May and June. Most slipper limpet females will spawn twice in a year, generally after neap tides.

Many different avenues can be ventured upon to find the perfect target market and the best way to market these shellfish. Slipper limpets are a versatile food. They have the flavor and individualism to stand alone as a main course, an appetizer or be incorporated into many different dishes. Before, during and after cooking, slipper limpets produce a good amount of liquid which can be boiled down into broth or stock. The liquid itself could also be used as a clam juice substitute...Recipes including limpets have been published in Scottish cookbooks; in Hawaii they are considered a delicacy and the Azores highly value them in their cultural dishes.

Although considered an invasive species, there are attempts to harvest and market the snail in France.