''Pagurus hirsutiusculus'' is a

species In biology, a species is the basic unit of Taxonomy (biology), 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 ...

hermit crab Hermit crabs are anomuran decapod crustaceans of the superfamily Paguroidea that have adapted to occupy empty scavenged mollusc shells to protect their fragile exoskeletons. There are over 800 species of hermit crab, most of which possess an a ...

, commonly called the hairy hermit crab. It lives from the Bering Strait south to

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the ...

and Japan, from the

intertidal zone The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species ...

to a depth of .

Description

Adults range in color from olive green to brown to black. Distinguishing characteristics of this hermit crab are white and often also blue bands on the walking legs. The antennae are grayish-brown with distinct white bands. This hermit crab is also easily identified by the remarkable amount of hair covering its body. The carapace of an adult ''P. hirsutiusculus'' may measure up to in length, and the animal's body may grow to in northern populations. Populations further south than

Puget Sound Puget Sound ( ) is a sound of the Pacific Northwest, an inlet of the Pacific Ocean, and part of the Salish Sea. It is located along the northwestern coast of the U.S. state of Washington. It is a complex estuarine system of interconnected m ...

are smaller and less hairy, and have been recognized as a separate subspecies, ''P. h. venturensis''.

Range and habitat

''P. hirsutiusculus'' is found from the

Pribilof Islands The Pribilof Islands (formerly the Northern Fur Seal Islands; ale, Amiq, russian: Острова Прибылова, Ostrova Pribylova) are a group of four volcanic islands off the coast of mainland Alaska, in the Bering Sea, about north of ...

, Alaska to southern alifornia and from the Bering Strait south to Japan. It lives at depths ranging from the middle

to , generally lower than ''

Pagurus samuelis ''Pagurus samuelis'', the blueband hermit crab, is a species of hermit crab from the west coast of North America, and the most common hermit crab in California. It is a small species, with distinctive blue bands on its legs. It prefers to live in ...

''. It is commonly found in tide pools with sand or rock, and under rocks, logs, and

seaweed Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of ''Rhodophyta'' (red), ''Phaeophyta'' (brown) and ''Chlorophyta'' (green) macroalgae. Seaweed species such as ke ...

, and is the common hermit crab of

San Francisco Bay San Francisco Bay is a large tidal estuary in the United States, U.S. state of California, and gives its name to the San Francisco Bay Area. It is dominated by the big cities of San Francisco, San Jose, California, San Jose, and Oakland, Ca ...

Natural history

As is common with hermit crabs, ''P. hirsutiusculus'' carries an abandoned

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 ...

to protect itself. Individuals from calmer waters will readily leave their shell when confronted with a predator, a trait which the authors of ''

Between Pacific Tides ''Between Pacific Tides'' is a 1939 book by Edward F. Ricketts and Jack Calvin that describes the intertidal ecology of the Pacific coast of the United States, Canada, and Mexico. The book was originally titled "Between Pacific Tides: An Accou ...

'' attributed to the lack of surf. the preferred shells are those of ''

Nassa Nassa may refer to: * Nassa, Noradrenergic and specific serotonergic antidepressant * Nassa (gastropod) ''Nassa'' is a genus of sea snails, marine gastropod mollusks in the subfamily Rapaninae of the family Muricidae, the murex snails or rock s ...

'', ''

Olivella biplicata ''Callianax biplicata'', common names the "purple dwarf olive" "purple olive shell" or "purple olivella" is a species of small predatory sea snail, a marine gastropod mollusc in the family Olividae, the olives. MolluscaBase eds. (2021). Mollu ...

'', '' Nucella emarginata'', ''

Tectarius striatus ''Tectarius striatus'' is a species of sea snail, a marine gastropod mollusk in the family Littorinidae, the winkles or periwinkles. It is endemic to Macaronesia (Azores, Madeira, Savage Islands, Canary Islands and Cape Verde , natio ...

'', ''

Epitonium tinctum ''Epitonium'' is a genus of small predatory sea snails, marine gastropod mollusks. ''Epitonium'' is the type genus of the family Epitoniidae, the wentletraps.Bouchet, P.; Gofas, S. (2010). Epitonium Röding, 1798. In: Bouchet, P.; Gofas, S.; Ro ...

'', '' Alia carinata'', '' Homalopoma luridum'', ''

Ilyanassa obsoleta The eastern mudsnail, ''Ilyanassa obsoleta'', is a species of sea snail, a marine gastropod mollusk in the family Nassariidae, the nassa mud snails.MolluscaBase eds. (2021). MolluscaBase. Ilyanassa obsoleta (Say, 1822). Accessed through: Worl ...

'', '' Urosalpinx cinerea'', and ''

Busycotypus canaliculatus ''Busycotypus canaliculatus'', commonly known as the channeled whelk, is a very large predatory sea snail, a marine prosobranch gastropod, a busycon whelk, belonging to the family Busyconidae.Fraussen, K.; Rosenberg, G. (2012). Busycotypus can ...

''. In the San Juan Archipelago, ''Pagurus hirsutiusculus'' has been found to carry the

parasitic Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson ha ...

isopod Isopoda is an order of crustaceans that includes woodlice and their relatives. Isopods live in the sea, in fresh water, or on land. All have rigid, segmented exoskeletons, two pairs of antennae, seven pairs of jointed limbs on the thorax, an ...

'' Pseudione giardi''. ''P. hirsutiusculus'' mainly feeds on

detritus In biology, detritus () is dead particulate organic material, as distinguished from dissolved organic material. Detritus typically includes the bodies or fragments of bodies of dead organisms, and fecal material. Detritus typically hosts commu ...

, but is an opportunistic feeder and also feeds on

s. The right chela of ''P. hirsutiusculus'' is significantly larger than the left and is used primarily for defense. The smaller left chela is used for fine motor work such as eating and selecting gastropod shells. The

setae In biology, setae (singular seta ; from the Latin word for " bristle") are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Annelid setae are stiff bristles present on the body. ...

on the minor chela are sensitive to

calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar t ...

, and help the hermit to judge whether the gastropod shell will be adequate to suit its needs.

References

External links

*
Link to Invertebrate Species Pages
{{Taxonbar, from=Q2287883 Hermit crabs Crustaceans of the eastern Pacific Ocean Crustaceans described in 1851

Description

Range and habitat

Natural history

References

Further reading

External links