''Pagurus forbesii'' is a species of hermit crab in the family

Paguridae The Paguridae are a family of hermit crabs of the order Decapoda. This family contains 542 species in over 70 genera:. The king crabs, Lithodoidea, are now widely undestood to be derived from deep within the Paguridae, with some authors placing t ...

. It is found in the northeastern Atlantic Ocean and the Mediterranean Sea.

Taxonomy

This species was first described by the English zoologist Thomas Bell, writing in the publication ''A history of British Crustacea IV''. Although the year is usually given as 1846, the part of this publication concerned was actually published in the last week of 1845. The type locality was Falmouth in England. Later in 1846, the French zoologist Hippolyte Lucas described ''Pagurus sculptimanus'' from

Oran Oran ( ar, وَهران, Wahrān) is a major coastal city located in the north-west of Algeria. It is considered the second most important city of Algeria after the capital Algiers, due to its population and commercial, industrial, and cultural ...

, and this was later determined to be a

synonym A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...

of ''P. forbesii''.

Description

The genus '' Pagurus'' consist of around 170 species including 13 found in the eastern Atlantic Ocean. Of these 13, ''Pagurus forbesii'' and '' Pagurus cuanensis'' are distinctive in having long eyestalks, and the males have characteristic

pleopod The decapod ( crustaceans such as a crab, lobster, shrimp or prawn) is made up of 20 body segments grouped into two main body parts: the cephalothorax and the pleon (abdomen). Each segment may possess one pair of appendages, although in various ...

s numbered 2 to 5 on the left. 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 ...

can grow to a length of about . The right chela (claw) is hairy and somewhat granulated; the propodus (penultimate segment) has a depression on either side of a long ridge that extends onto the

dactylus The dactylus is the tip region of the tentacular club of cephalopods and of the leg of some crustaceans (see arthropod leg). In cephalopods, the dactylus is narrow and often characterized by the asymmetrical placement of suckers (i.e., the ve ...

. The visible portions of this hermit crab are reddish yellow, with darker spotting being present on the abdomen.

Distribution and habitat

''Pagurus forbesii'' occurs in the northeastern Atlantic Ocean and the Mediterranean Sea, its depth range being . It inhabits sandy seabeds with coarse and medium-sized grains, as well as coral rubble.

Ecology

Like other hermit crabs, ''P. forbesii'' uses the empty shells of gastropod molluscs to live in. This crab has been found inhabiting shells of the cornet (''

Cerithium vulgatum ''Cerithium vulgatum'' is a species of sea snail, a marine gastropod mollusk in the family Cerithiidae. Description Distribution This species occurs in European waters and in the Mediterranean Sea The Mediterranean Sea is a sea connecte ...

''), the thick-lipped dogwhelk (''

Tritia incrassata ''Tritia incrassata'', common name the thick-lipped dogwhelk, is a species of small sea snail, a marine gastropod mollusk in the family Nassariidae, the Nassa mud snails or dog whelks.Marshall, B. (2016). Tritia incrassata (Strøm, 1768). Access ...

''), the common tower shell (''

Turritella communis ''Turritella communis'', common name the "common tower shell" is a species of medium-sized sea snails with an operculum, marine gastropod mollusks in the family Turritellidae. Distribution and habitat This species occurs in the Eastern Atlan ...

'') and ''

Ocinebrina aciculata ''Ocinebrina aciculata'' is a species of sea snail, a marine gastropod mollusk in the family (biology), family Muricidae, the murex snails or rock snails. Subspecies and varieties * ''Ocinebrina aciculata aciculata'' (Lamarck, 1822): synonym o ...

''. The

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 ...

Adamsia palliata ''Adamsia palliata'' is a species of sea anemone in the family Hormathiidae. It is usually found growing on a gastropod shell inhabited by the hermit crab, '' Pagurus prideaux''. The anemone often completely envelops the shell and because of thi ...

'' often lives on the shell occupied by a hermit crab; usually this is a shell used by ''

Pagurus prideaux ''Pagurus prideaux'' is a species of hermit crab in the family Paguridae. It is found in shallow waters off the northwest coast of Europe and usually lives symbiotically with the sea anemone ''Adamsia palliata''. Description Like other hermi ...

'', but in the

Bay of Naples A bay is a recessed, coastal body of water that directly connects to a larger main body of water, such as an ocean, a lake, or another bay. A large bay is usually called a gulf, sea, sound, or bight. A cove is a small, circular bay with a narr ...

in Italy, about 8% of the shells occupied by ''P. forbesii'' were found to be colonised by the sea anemone. Three species of hermit crab were found to be present in a bay near Cadiz in southern Spain. ''

Paguristes eremita ''Paguristes eremita'', the eye spot hermit crab, is a species of hermit crab in the family Diogenidae. It is found in the Mediterranean Sea. Description The carapace of this hermit crab can grow to a length of about . The rostrum is pointed a ...

'' were the biggest and positively selected the largest and most robust available gastropod shells. ''

Diogenes pugilator ''Diogenes pugilator'' is a species of hermit crab, sometimes called the small hermit crab or south-claw hermit crab. It is found from the coast of Angola to as far north as the North Sea, and eastwards through the Mediterranean Sea, Black Sea an ...

'' and ''P. forbesii'' occupied similar-size, lighter shells, but despite being much more abundant, ''D. pugilator'' tended not to inhabit the commonest shell ''

Turritella turbona ''Turritella turbona'' is a species of sea snail, a marine gastropod mollusk in the family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relation ...

'', while ''P. forbesii'' seemed to preferentially select them. On occasions, ''D. pugilator'' continued to inhabit a shell whose aperture it had outgrown, while ''P. forbesii'' and ''P. eremita'' moved on to larger shells as they grew.

References

{{Taxonbar, from=Q13988210 Hermit crabs Crustaceans of the Atlantic Ocean Fauna of the Mediterranean Sea Crustaceans described in 1845 Taxa named by Thomas Bell (zoologist)