''Pagurus samuelis'', the blueband hermit crab, 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 ...

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 the shell of the black turban snail, and is a nocturnal

scavenger Scavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a herbivorous feeding b ...

of algae and carrion.

Description

''Pagurus samuelis'' is a small hermit crab, at up to a total length of and a

carapace A carapace is a 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 tortoises, the und ...

width of up to . The base colour of the

exoskeleton An exoskeleton (from Greek ''éxō'' "outer" and ''skeletós'' "skeleton") is an external skeleton that supports and protects an animal's body, in contrast to an internal skeleton ( endoskeleton) in for example, a human. In usage, some of the ...

is brown or green, but the antennae are red, and adults have bright blue bands near the tips of their legs. In smaller individuals, the bands may be white. The legs and carapace are covered in setae, and the rostrum at the front of the carapace is triangular.

Distribution

''Pagurus samuelis'' is found from

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S ...

Punta Eugenia Punta Eugenia is a headland in the Mulegé Municipality. It marks the Western tip of the Vizcaíno Peninsula, thus being the westernmost point on the mainland of the state of Baja California Sur. It belongs to the larger area of El Vizcaíno Bio ...

Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...

Mexico Mexico ( Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guate ...

. It was formerly thought to also occur in Japan, but the Japanese specimens which were formerly assigned to this species are now recognised as ''

Pagurus filholi ''Pagurus'' is a genus of hermit crabs in the family Paguridae. Like other hermit crabs, their abdomen is not calcified and they use snail shells as protection. These marine decapod crustaceans are omnivorous, but mostly prey on small animals ...

''.

Ecology and life cycle

Hermit crabs scavenge at Gumboot chiton 2

''Pagurus samuelis'' prefers to use the discarded

shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses ** Thin-shell structure Science Biology * Seashell, a hard o ...

of the black turban snail, ''Tegula funebralis''. They are chiefly

nocturnal Nocturnality is an ethology, animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite. Nocturnal creatures generally have ...

s that feed on

algae Algae ( , ; : alga ) are any of a large and diverse group of photosynthetic, eukaryotic organisms. The name is an informal term for a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from ...

, especially the giant kelp ''

Macrocystis pyrifera ''Macrocystis pyrifera'', commonly known as giant kelp or bladder kelp, is a species of kelp (large brown algae), and one of four species in the genus '' Macrocystis''. Despite its appearance, it is not a plant; it is a heterokont. Giant kelp ...

'', and

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 ...

. In a laboratory setting, ''P. samuelis'' can survive on a diet of ''

Pelvetia canaliculata ''Pelvetia canaliculata'', the channelled wrack, is a very common brown alga (Phaeophyceae) found on the rocks of the upper shores of Europe. It is the only species remaining in the monotypic genus ''Pelvetia''. In 1999, the other members of th ...

''.

Predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill ...

s of ''P. samuelis'' include fishes such as the pile perch ('' Rhacochilus vacca''), California sheephead (''Semicossyphus pulcher'') and the spotted kelpfish, '' Gibbonsia elegans''. In the

breeding season Seasonal breeders are animal species that successfully mate only during certain times of the year. These times of year allow for the optimization of survival of young due to factors such as ambient temperature, food and water availability, and ch ...

, males carry females on their backs, sometimes for more than a day.

Eggs Humans and human ancestors have scavenged and eaten animal eggs for millions of years. Humans in Southeast Asia had domesticated chickens and harvested their eggs for food by 1,500 BCE. The most widely consumed eggs are those of fowl, especial ...

are produced from May to July, and are carried on the female's abdomen, inside the shell.

References

External links

* * * * {{Taxonbar, from=Q3360483 Hermit crabs Crustaceans of the eastern Pacific Ocean Crustaceans described in 1857

Description

Distribution

Ecology and life cycle

See also

References

External links