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The common slipper shell, (Crepidula fornicata), has many other common names, including common Atlantic slippersnail, boat shell, quarterdeck shell, fornicating slipper snail, Atlantic slipper limpet and it is known in Britain as the "common slipper limpet". This is a species of medium-sized sea snail, a marine gastropod mollusc in the family Calyptraeidae, the slipper snails and cup and saucer snails.

Common slipper shell
Crépidules groupe.jpg
A stack of Crepidula fornicata. The small one on the left is a male, the oval animal at the top left is a chiton.
Scientific classification
C. fornicata
Binomial name
Crepidula fornicata
(Linnaeus, 1758)


10 fresh shells of Crepidula fornicata

The size of the shell is 20–50 mm.[1] The maximum recorded shell length is 56 mm.[2]

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).[3]


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[1] from as far north as Nova Scotia to as far south as the Gulf of Mexico.[1] It has been introduced accidentally to other parts of the world and has become problematic.

Nonindigenous distributionEdit

Five views of a shell of Crepidula fornicata

It was introduced to the state of Washington.[1] The species was, however, brought to Europe together with the eastern oyster Crassostrea virginica.[1] In Belgium, the first slipper limpet was found on September 28, 1911, attached to an oyster in Ostend, and since the 1930s it is seen as a common species along the Belgian coast.[1]

The species is considered an invasive species in Denmark, France, Italy, the Netherlands, Spain, and the United Kingdom, and has also spread to Norway and Sweden.[4] It is known to damage oyster fisheries.[5] The slipper limpet has few to no predators in Europe, and can thrive on several types of hard bottoms and shellfish banks.[1] A continued expansion to the north is probably inhibited by temperature: low temperatures during the winter can slow down or inhibit the development of the slipper limpet.[1] It has also been introduced to the Pacific Northwest and Japan.[6]

Human consumptionEdit

Culinary useEdit

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. We believe these shellfish delicacies have the potential to fill a niche in seafood market. If expressed to the public correctly, people will embrace this new shellfish and a demand for Crepidula fornicata will result in vastly increasing commercial and restaurant sales. Therefore, this shellfish and its recipes could become commercially important in the years to come. 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.[7]

Although considered an invasive species, there are attempts to harvest and market the snail in France.[8]



This is a common snail, usually found intertidally, infralittoral and circalittoral and in estuaries.[1]

Minimum recorded depth is 0 m.[2] Maximum recorded depth is 70 m.[2]

They are often found, sometimes living stacked on top of one another, on rocks,[1] on horseshoe crabs, shells and on dock pilings.

Feeding habitsEdit

Generally for Calyptraeidae, feeding habits include planktonic and minute detrital food items through either suspension or deposit feeding.[1]

Life cycleEdit

The species is a sequential hermaphrodite. 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.[9]


This article incorporates CC-BY-SA-3.0 text from the reference [1]

  1. ^ a b c d e f g h i j k l Gofas, S. (2010). Crepidula fornicata (Linnaeus, 1758). In: Bouchet, P.; Gofas, S.; Rosenberg, G. (2010) World Marine Mollusca database. Accessed through: World Register of Marine Species at on January 13, 2011
  2. ^ a b c Welch J. J. (2010). "The "Island Rule" and Deep-Sea Gastropods: Re-Examining the Evidence". PLoS ONE 5(1): e8776. doi:10.1371/journal.pone.0008776.
  3. ^ "Crepidula fornicata (Linnaeus, 1758)". Retrieved February 20, 2015.
  4. ^ Global Invasive Species Database
  5. ^ Joint Nature Conservation Committee
  6. ^ "Marine Life Information Network for Britain and Ireland". Archived from the original on February 7, 2012. Retrieved October 7, 2007.
  7. ^ Roger Williams University's report.
  8. ^ Lalita Clozel (March 12, 2014), In France, a Quest to Convert a Sea Snail Plague Into a Culinary Pleasure, The New York Times
  9. ^ Global Invasive Species Database

External linksEdit