''Paguristes eremita'', the eye spot hermit crab, is a

species In biology, a species is the basic unit of 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 the appropriate s ...

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 as ...

in the family

Diogenidae The Diogenidae are a family of hermit crabs, sometimes known as "left-handed hermit crabs" because in contrast to most other hermit crabs, its left chela (claw) is enlarged instead of the right. It comprises 429 extant species, and a further 4 ...

. It is found in the

Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ...

Description

The carapace of this hermit crab can grow to a length of about . The rostrum is pointed and there is a spine at the tip of the small eye scale. The eye stalks are long and cylindrical and the antennal scales are thorny and nearly cover the bases of the antennae. The

chelae A chela ()also called a claw, nipper, or pinceris a pincer (biology), pincer-like organ at the end of certain limbs of some arthropods. The name comes from Ancient Greek , through New Latin '. The plural form is chelae. Legs bearing a chela are ...

(claws) are granulated and covered with short hairs. The left chela is slightly larger than the right one. The walking legs are laterally compressed; the first three pairs are similar in length, the fourth pair are much shorter and the fifth pair end in small claws. The general colour of this crab is orange-red to brown, and the eyes are greyish-blue. A purplish spot at the base of the dactylus is diagnostic of this species.

Distribution and habitat

''Paguristes eremita'' is native to the

and adjoining Atlantic Ocean, where its range extends from Portugal to Morocco. Its depth range is and it occurs on sandy stretches of seabed and in

seagrass meadow A seagrass meadow or seagrass bed is an underwater ecosystem formed by seagrasses. Seagrasses are marine (saltwater) plants found in shallow coastal waters and in the brackish waters of estuaries. Seagrasses are flowering plants with stems and ...

s among the Neptune grass.

Ecology

Like other hermit crabs, ''P. eremita'' inhabits the empty shell of a gastropod mollusc. It is often associated with the sea anemone ''

Calliactis parasitica ''Calliactis parasitica'' is a species of sea anemone associated with hermit crabs. It lives in the eastern Atlantic Ocean and Mediterranean Sea at depths between the intertidal zone and . It is up to in size, with up to 700 tentacles, and is ...

'', epizoanthids,

hydroids Hydroids are a life stage for most animals of the class Hydrozoa, small predators related to jellyfish. Some hydroids such as the freshwater '' Hydra'' are solitary, with the polyp attached directly to the substrate. When these produce buds ...

or the sponge '' Suberites domuncula'' which attach themselves to the shell. The main predators on this crab are

loggerhead turtle The loggerhead sea turtle (''Caretta caretta'') is a species of oceanic turtle distributed throughout the world. It is a marine reptile, belonging to the family Cheloniidae. The average loggerhead measures around in carapace length when fully ...

s, larger

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group can ...

s, octopuses and certain fish. Like other crabs, ''P. eremita'' is a detritivore. Breeding takes place all year round. The larvae are planktonic and pass through two zoea larval stages and one

megalopa Crustaceans may pass through a number of larval and immature stages between hatching from their eggs and reaching their adult form. Each of the stages is separated by a moult, in which the hard exoskeleton is shed to allow the animal to grow. The ...

stage before undergoing metamorphosis into juvenile hermit crabs.

References

{{Taxonbar, from=Q3888980 Hermit crabs Crustaceans of the Atlantic Ocean Crustaceans described in 1767 Taxa named by Carl Linnaeus