Dardanus pedunculatus
Encyclopedia
Dardanus pedunculatus, the anemone hermit crab, is a species of hermit crab
from the Indo-Pacific
region. It lives at depths of up to 27 m and collects sea anemone
s to place on its shell for defence.
region, from the Seychelles
in the west to Japan
and Hawaii
in the east. In Australia
, it is found from New South Wales
(as far south at Port Jackson
) to Queensland
.
s and in the intertidal zone
, at depths of 1–27 m (3.3–88.6 ft). It usually carries sea anemone
s on its shell, which it uses to protect itself from its main predator, cephalopod
s of the genus Octopus. 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
that the hermit crab inhabits.
is mottled in tan and cream, while the eyestalk
s are white with red bands. The sexes are similar. The left claw
is much larger than the right claw.
s are popular pets in marine aquaria, and Dardanus pedunculatus is occasionally kept, although the species has not been successfully reared in captivity.
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
and Neopagurus, and a number of taxonomic synonyms
have been created.
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:...
from the Indo-Pacific
Indo-Pacific
The Indo-Pacific is a biogeographic region of the Earth's seas, comprising the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the seas connecting the two in the general area of Indonesia...
region. It lives at depths of up to 27 m and collects sea anemone
Sea anemone
Sea anemones are a group of water-dwelling, predatory animals of the order Actiniaria; they are named after the anemone, a terrestrial flower. Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Zoantharia. Anthozoa often have large polyps that allow for digestion of larger...
s to place on its shell for defence.
Distribution
Dardanus pedunculatus has a broad distribution in the Indo-PacificIndo-Pacific
The Indo-Pacific is a biogeographic region of the Earth's seas, comprising the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the seas connecting the two in the general area of Indonesia...
region, from the Seychelles
Seychelles
Seychelles , officially the Republic of Seychelles , is an island country spanning an archipelago of 115 islands in the Indian Ocean, some east of mainland Africa, northeast of the island of Madagascar....
in the west 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...
and Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
in the east. In Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, it is found from New South Wales
New South Wales
New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...
(as far south at Port Jackson
Port Jackson
Port Jackson, containing Sydney Harbour, is the natural harbour of Sydney, Australia. It is known for its beauty, and in particular, as the location of the Sydney Opera House and Sydney Harbour Bridge...
) to Queensland
Queensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...
.
Ecology
D. pedunculatus usually lives on coral reefCoral reef
Coral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps...
s and in 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...
, at depths of 1–27 m (3.3–88.6 ft). It usually carries sea anemone
Sea anemone
Sea anemones are a group of water-dwelling, predatory animals of the order Actiniaria; they are named after the anemone, a terrestrial flower. Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Zoantharia. Anthozoa often have large polyps that allow for digestion of larger...
s on its shell, which it uses to protect itself from its main predator, cephalopod
Cephalopod
A cephalopod is any member of the molluscan class Cephalopoda . These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles modified from the primitive molluscan foot...
s of the genus Octopus. The anemones are collected at night, and comprises the crab stroking and tapping the anemone until it loosens its grip on the substrate
Substrate (biology)
In biology a substrate is the surface a plant or animal lives upon and grows on. A substrate can include biotic or abiotic materials and animals. For example, encrusting algae that lives on a rock can be substrate for another animal that lives on top of the algae. See also substrate .-External...
, at which point it is moved onto the gastropod shell
Gastropod 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...
that the hermit crab inhabits.
Description
Dardanus pedunculatus usually attain a maximum size of 10 centimetres (4 in). The carapaceCarapace
A carapace is a dorsal 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 underside is called the plastron.-Crustaceans:In crustaceans, the...
is mottled in tan and cream, while the eyestalk
Eyestalk
In anatomy, an eyestalk is a protrusion that extends the eye away from the body, giving the eye a better field of view than if it were unextended. It is common in nature and in fiction....
s are white with red bands. The sexes are similar. The left claw
Claw
A claw is a curved, pointed appendage, found at the end of a toe or finger in most mammals, birds, and some reptiles. However, the word "claw" is also often used in reference to an invertebrate. Somewhat similar fine hooked structures are found in arthropods such as beetles and spiders, at the end...
is much larger than the right claw.
Pets
Hermit crabHermit 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:...
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 HerbstJohann Friedrich Wilhelm Herbst
Johann Friedrich Wilhelm Herbst was a German naturalist and entomologist from Petershagen, Minden-Ravensberg....
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
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 portable homes. These marine decapod crustaceans are omnivorous, but mostly prey on small animals and scavenge carrion...
and Neopagurus, and a number of taxonomic synonyms
Synonym (taxonomy)
In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...
have been created.