Pagurus hirsutiusculus
Encyclopedia
Pagurus hirsutiusculus is a species
of hermit crab
, commonly called the hairy hermit crab. It lives from the Bering Strait
south to California
and Japan
, from the intertidal zone
to a depth of 110 m (360.9 ft).
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 19 mm (0.748031496062992 in) in length, and the animal's body may grow to 70 mm (2.8 in) in northern populations. Populations further south than Puget Sound
are smaller and less hairy, and have been recognized as a separate subspecies, P. h. venturensis.
, Alaska to southern California
, and from the Bering Strait
south to Japan
. It lives at depths ranging from the middle intertidal zone
to 110 m (360.9 ft), generally lower than Pagurus samuelis
. Is is commonly found in tide pools with sand or rock, and under rocks, logs, and seaweed
, and is the common hermit crab of San Francisco Bay
.
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
attributed to the lack of surf
. the preferred shells are those of Nassa
, Olivella biplicata
, Nucella emarginata
, Tectarius striatus
, Epitonium tinctum, Alia carinata
, Homalopoma luridum, Ilyanassa obsoleta, Urosalpinx cinerea
, and Busycotypus canaliculatus
. In the San Juan Archipelago, Pagurus hirsutiusculus has been found to carry the parasitic
isopod
Pseudione giardi.
P. hirsutiusculus mainly feeds on detritus
, but is an opportunistic feeder and also feeds on seaweed
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 on the minor chela are sensitive to calcium
, and help the hermit to judge whether the gastropod shell will be adequate to suit its needs.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of hermit crab
Hermit crab
Hermit crabs are decapod crustaceans of the superfamily Paguroidea. Most of the 1100 species possess an asymmetrical abdomen which is concealed in an empty gastropod shell that is carried around by the hermit crab.-Description:...
, commonly called the hairy hermit crab. It lives from the Bering Strait
Bering Strait
The Bering Strait , known to natives as Imakpik, is a sea strait between Cape Dezhnev, Chukotka Autonomous Okrug, Russia, the easternmost point of the Asian continent and Cape Prince of Wales, Alaska, USA, the westernmost point of the North American continent, with latitude of about 65°40'N,...
south to California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
and Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, from the intertidal zone
Intertidal zone
The intertidal zone is the area that is above water at low tide and under water at high tide . This area can include many different types of habitats, with many types of animals like starfish, sea urchins, and some species of coral...
to a depth of 110 m (360.9 ft).
Description
Antenna (biology)
Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....
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 19 mm (0.748031496062992 in) in length, and the animal's body may grow to 70 mm (2.8 in) in northern populations. Populations further south than Puget Sound
Puget Sound
Puget Sound is a sound in the U.S. state of Washington. It is a complex estuarine system of interconnected marine waterways and basins, with one major and one minor connection to the Strait of Juan de Fuca and the Pacific Ocean — Admiralty Inlet being the major connection and...
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 IslandsPribilof Islands
The Pribilof Islands are a group of four volcanic islands off the coast of mainland Alaska, in the Bering Sea, about north of Unalaska and 200 miles southwest of Cape Newenham. The Siberia coast is roughly northwest...
, Alaska to southern California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, and from the Bering Strait
Bering Strait
The Bering Strait , known to natives as Imakpik, is a sea strait between Cape Dezhnev, Chukotka Autonomous Okrug, Russia, the easternmost point of the Asian continent and Cape Prince of Wales, Alaska, USA, the westernmost point of the North American continent, with latitude of about 65°40'N,...
south to Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
. It lives at depths ranging from the middle intertidal zone
Intertidal zone
The intertidal zone is the area that is above water at low tide and under water at high tide . This area can include many different types of habitats, with many types of animals like starfish, sea urchins, and some species of coral...
to 110 m (360.9 ft), generally lower than Pagurus samuelis
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...
. Is is commonly found in tide pools with sand or rock, and under rocks, logs, and seaweed
Seaweed
Seaweed is a loose, colloquial term encompassing macroscopic, multicellular, benthic marine algae. The term includes some members of the red, brown and green algae...
, and is the common hermit crab of San Francisco Bay
San Francisco Bay
San Francisco Bay is a shallow, productive estuary through which water draining from approximately forty percent of California, flowing in the Sacramento and San Joaquin rivers from the Sierra Nevada mountains, enters the Pacific Ocean...
.
Natural history
As is common with hermit crabs, P. hirsutiusculus carries an abandoned gastropod shellGastropod shell
The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...
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
Between Pacific Tides is a 1939 book by Ed Ricketts and Jack Calvin that explores the intertidal ecology of the Pacific coast of the United States...
attributed to the lack of surf
Surf
Surf is the wave activity in the area between the shoreline and outer limit of breakers. It may refer to a breaking wave in shallow water, upon the shore, or in the area in which waves breakSurf also may refer to:Commercial products...
. the preferred shells are those of Nassa
Nassa (gastropod)
Nassa is a genus of sea snails, marine gastropod mollusks in the family Muricidae, the murex snails or rock snails.The history of the name Nassa is rather confused, because the name was allocated twice:...
, Olivella biplicata
Olivella biplicata
Olivella 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 Olivellidae, the dwarf olives.-Distribution:...
, Nucella emarginata
Nucella emarginata
Nucella emarginata, common name : the Emarginate Dog Winkle, is a species of sea snail, a marine gastropod mollusk in the family Muricidae, the murex snails or rock snails.-External links:*...
, Tectarius striatus
Tectarius striatus
Tectarius striatus is a species of sea snail, a marine gastropod mollusk in the family Littorinidae, the winkles or periwinkles....
, Epitonium tinctum, Alia carinata
Alia carinata
Alia carinata, common name the "carinate dove shell", is a species of very small sea snail, a marine gastropod mollusk in the family Columbellidae, the dove snails.-Distribution:...
, Homalopoma luridum, Ilyanassa obsoleta, Urosalpinx cinerea
Urosalpinx cinerea
Urosalpinx cinerea, common name the eastern or Atlantic oyster drill, is a species of small predatory sea snail, a marine gastropod mollusk in the family Muricidae, the murexes or rock snails....
, and Busycotypus canaliculatus
Channeled whelk
The channeled whelk, Busycotypus canaliculatus, previously known as Busycon canaliculatum, is a very large predatory sea snail, a marine prosobranch gastropod, a busycon whelk, belonging to the family Buccinidae. This species is edible....
. In the San Juan Archipelago, Pagurus hirsutiusculus has been found to carry the parasitic
Parasitism
Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that needed more than one host . These are now called macroparasites...
isopod
Isopoda
Isopods are an order of peracarid crustaceans, including familiar animals such as woodlice and pill bugs. The name Isopoda derives from the Greek roots and...
Pseudione giardi.
P. hirsutiusculus mainly feeds on detritus
Detritus
Detritus is a biological term used to describe dead or waste organic material.Detritus may also refer to:* Detritus , a geological term used to describe the particles of rock produced by weathering...
, but is an opportunistic feeder and also feeds on seaweed
Seaweed
Seaweed is a loose, colloquial term encompassing macroscopic, multicellular, benthic marine algae. The term includes some members of the red, brown and green algae...
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 on the minor chela are sensitive to calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
, and help the hermit to judge whether the gastropod shell will be adequate to suit its needs.