''Dardanus pedunculatus'', the anemone hermit crab, is a species 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

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

region. It lives at depths of up to 27 m and collects

sea anemone Sea anemones are a group of predation, predatory marine invertebrates of the order (biology), order Actiniaria. Because of their colourful appearance, they are named after the ''Anemone'', a terrestrial flowering plant. Sea anemones are classifi ...

s to place on its shell for defence.

Distribution

''Dardanus pedunculatus'' has a broad distribution in the

region, from the

Seychelles Seychelles (, ; ), officially the Republic of Seychelles (french: link=no, République des Seychelles; Creole: ''La Repiblik Sesel''), is an archipelagic state consisting of 115 islands in the Indian Ocean. Its capital and largest city, V ...

in the west to

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

and

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...

in the east. In

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

, it is found from

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

(as far south at

Port Jackson Port Jackson, consisting of the waters of Sydney Harbour, Middle Harbour, North Harbour and the Lane Cove and Parramatta Rivers, is the ria or natural harbour of Sydney, New South Wales, Australia. The harbour is an inlet of the Tasman Sea (p ...

) to

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

Ecology

''D. pedunculatus'' usually lives on

coral reef A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups. Co ...

s and in 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 o ...

, at depths of . It usually carries

s on its shell, which it uses to protect itself from its main

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 th ...

cephalopod A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head ...

s of the genus ''

Octopus An octopus ( : octopuses or octopodes, see below for variants) is a soft-bodied, eight- limbed mollusc of the order Octopoda (, ). The order consists of some 300 species and is grouped within the class Cephalopoda with squids, cuttle ...

''. The anemones are collected at night, and comprises the crab stroking and tapping the anemone until it loosens its grip on the substrate, at which point it is moved onto the

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 ...

that the hermit crab inhabits.

Description

''Dardanus pedunculatus'' usually attain a maximum size of . The

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 ...

mottled Mottle is a pattern of irregular marks, spots, streaks, blotches or patches of different shades or colours. It is commonly used to describe the surface of plants or the skin of animals. In plants, mottling usually consists of yellowish spots o ...

in tan and cream, while the

eyestalk In anatomy, an eyestalk (sometimes spelled eye stalk and also known as an ommatophore) is a protrusion that extends an eye away from the body, giving the eye a better field of view. It is a common feature in nature and frequently appears in fic ...

s are white with red bands. The sexes are similar. The left

claw A claw is a curved, pointed appendage found at the end of a toe or finger in most amniotes (mammals, reptiles, birds). Some invertebrates such as beetles and spiders have somewhat similar fine, hooked structures at the end of the leg or tarsus ...

is much larger than the right claw.

Pets

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 ...

s are popular pets in marine aquaria, and ''Dardanus pedunculatus'' is occasionally kept, although the species has not been successfully reared in captivity.

Taxonomic history

''Dardanus pedunculatus'' was first described by

Johann Friedrich Wilhelm Herbst Johann Friedrich Wilhelm Herbst (1 November 1743 – 5 November 1807) was a German naturalist and entomologist from Petershagen, Minden-Ravensberg. He served as a chaplain in the Prussian army. His marriage in Berlin, 1770, with Euphrosyne Luise ...

as ''Cancer pedunculatus'', in his 1804 work '; the type locality is not known. It has since been placed in a number of different genera, including ''

Pagurus ''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 a ...

'' and '' Neopagurus'', and a number of taxonomic synonyms have been created.

References

External links

* {{Taxonbar, from=Q3012118 Hermit crabs Symbiosis Crustaceans described in 1804