''Clibanarius erythropus'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of hermit crab that lives in rockpools and sublittoral waters. It is found in the

Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ea ...

Black Sea The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Roma ...

and eastern

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

from the

Azores ) , motto =( en, "Rather die free than subjected in peace") , anthem= ( en, "Anthem of the Azores") , image_map=Locator_map_of_Azores_in_EU.svg , map_alt=Location of the Azores within the European Union , map_caption=Location of the Azores wi ...

Brittany Brittany (; french: link=no, Bretagne ; br, Breizh, or ; Gallo language, Gallo: ''Bertaèyn'' ) is a peninsula, Historical region, historical country and cultural area in the west of modern France, covering the western part of what was known ...

, the

Channel Islands The Channel Islands ( nrf, Îles d'la Manche; french: îles Anglo-Normandes or ''îles de la Manche'') are an archipelago in the English Channel, off the French coast of Normandy. They include two Crown Dependencies: the Bailiwick of Jersey, ...

and as far north as the south

Cornwall Cornwall (; kw, Kernow ) is a historic county and ceremonial county in South West England. It is recognised as one of the Celtic nations, and is the homeland of the Cornish people. Cornwall is bordered to the north and west by the Atlantic ...

coast. Individuals may grow up to a

carapace A carapace is a Dorsum (biology), dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tor ...

length of . Clibanarius_erythropus_2009_G3

Ecology

A variety of different

gastropod shell The gastropod shell is part of the body of a Gastropoda, gastropod or snail, a kind of mollusc. The shell is an exoskeleton, which protects from predators, mechanical damage, and dehydration, but also serves for muscle attachment and calcium s ...

s are used by ''C. erythropus'', the most frequent being ''

Littorina striata ''Littorina'' is a genus of small sea snails, marine gastropod molluscs in the family Littorinidae, the winkles or periwinkles.WoRMS (2011). Littorina Férussac, 1822. Accessed through: World Register of Marine Species at http://www.marinespecies ...

'', ''

Mitra ''Mitra'' ( Proto-Indo-Iranian: ''*mitrás'') is the name of an Indo-Iranian divinity from which the names and some characteristics of Rigvedic Mitrá and Avestan Mithra derive. The names (and occasionally also some characteristics) of these t ...

'', ''

Nassarius incrassatus ''Tritia incrassata'', common name the thick-lipped dogwhelk, is a species of small sea snail, a marine gastropod mollusk in the family Nassariidae, the Nassa mud snails or dog whelks.Marshall, B. (2016). Tritia incrassata (Strøm, 1768). Access ...

'' and '' Stramonita haemastoma'', which collectively account for 85% of all the individuals studied in the

; in the Mediterranean, shells of '' Cerithium'', ''

Alvania montagui ''Alvania'' is a genus of minute sea snails, marine gastropod mollusks or micromollusks in the family Rissoidae. ''Alvania'' as currently used may not be monophyletic. Distribution These marine species can be found worldwide (except in the An ...

'' and ''

Pisania maculosa ''Pisania'' is a genus of marine whelk in the family Pisaniidae. Some species prey on barnacles. Species According to the World Register of Marine Species (WoRMS) species with accepted names within the genus ''Pisania'' include: * '' Pisania an ...

'' are most used by ''C. erythropus''. Like other hermit crabs, ''C. erythropus'' feeds on "organic debris, decayed and fresh macro-algae with associated fauna and epiphytic algal flora, small invertebrates, and macroscopic pieces of dead and live animal tissues". It has been shown that ''C. erythropus'' individuals select substrates where they can cover large distances, and that

globose A sphere () is a geometrical object that is a three-dimensional analogue to a two-dimensional circle. A sphere is the set of points that are all at the same distance from a given point in three-dimensional space.. That given point is the ce ...

shells allow them greater mobility than elongate ones.

In popular culture

In 2016 the '' BBC Springwatch'' programme highlighted ''C. erythropus'' and ran a competition to provide a vernacular name. The winning name was St Piran's crab, a process supported by National Trust West Cornwall and the

Cornwall Wildlife Trust The Cornwall Wildlife Trust is a charitable organisation founded in 1962 that is concerned solely with Cornwall, England. It deals with the conservation and preservation of Cornwall's wildlife, geology and habitats managing over 50 nature reser ...

. Saint Piran is generally regarded as the

patron saint A patron saint, patroness saint, patron hallow or heavenly protector is a saint who in Catholicism, Anglicanism, or Eastern Orthodoxy is regarded as the heavenly advocate of a nation, place, craft, activity, class, clan, family, or perso ...

of Cornwall, and was a hermit who survived being thrown into the sea.http://ntwestcornwall.co.uk/?p=2292 the Incredible Life of a Rockpool

References

{{Taxonbar, from=Q3680644 Hermit crabs Crustaceans of the Atlantic Ocean Crustaceans described in 1818 Taxa named by Pierre André Latreille