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 asymmetric abdomen concealed by a snug-fitting shell. Hermit crabs' soft (non-calcified) abdominal exoskeleton means they must occupy shelter produced by other organisms or risk being defenseless.
The halloween hermit crab, also known as the striped hermit crab or orange-legged hermit crab, is a brightly colored aquatic hermit crab of the family Diogenidae. Besides its ability to routinely clean algae in aquaria, the halloween hermit crab's festive striped coloration also appeals to enthusiasts; it is considered the most brightly colored hermit crab in normal aquarium use.
Clibanarius is a genus of hermit crabs in the family Diogenidae. Like other hermit crabs, their abdomen is soft-shelled and sheltered in a gastropod shell. Typically marine like all their relatives, the genus includes C. fonticola, the only known hermit crab species that spends all its life in freshwater. The feeding rates of Clibanarius species change with temperature which, given their broad distributions, may have considerable consequences for the stability reef systems as sea temperatures rise in the future.
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 46 extinct species, making it the second-largest family of marine hermit crabs, after the Paguridae.
Clibanarius erythropus is a species of hermit crab that lives in rockpools and sublittoral waters. It is found in the Mediterranean Sea, Black Sea and eastern Atlantic Ocean from the Azores to Brittany, the Channel Islands and as far north as the south Cornwall coast. Individuals may grow up to a carapace length of 15 millimetres (0.6 in).
The Pylochelidae are a family of hermit crabs. Its members are commonly called the 'symmetrical hermit crabs'. They live in all the world's oceans, except the Arctic and the Antarctic, at depths of 2,000 m (6,600 ft). Due to their cryptic nature and relative scarcity, only around 60 specimens had been collected before 1987, when a monograph was published detailing a further 400.
Dardanus megistos, the white-spotted hermit crab or spotted hermit crab, is a species of hermit crab belonging to the family Diogenidae.
The Aeglidae are a family of freshwater crustaceans currently restricted to South America. They are the only anomurans to be found in fresh water except for a single hermit crab species, Clibanarius fonticola, on Espiritu Santo, Vanuatu. They live between 20° S and 50° S, at altitudes between 320 and 3,500 m (1,050–11,480 ft).
Ciliopagurus is a genus of hermit crabs, of the family Diogenidae, which are sometimes referred to as the "left-handed hermit crabs", because in contrast to most other hermit crabs, the left chela (claw) is enlarged instead of the right. They are found in the Indo-Pacific region and in the eastern Atlantic Ocean.
Ciliopagurus galzini is a species of hermit crab. It is one of four species in the "strigatus complex"; it resembles C. strigatus, with the most prominent difference being coloration. It is common in the shallow intertidal waters of the Tuamotus.
Ciliopagurus substriatiformis was a species of hermit crab that existed during the Badenian stage.
Clibanarius digueti is a species of hermit crab that lives off the western coast of Mexico, and is abundant in the Gulf of California. It is known under various common names such as the Mexican hermit crab, the blue-eyed spotted hermit or the Gulf of California hermit crab.
The Pylojacquesidae are a small family of hermit crabs, comprising only two monotypic genera. The family was erected in 2001, after two specimens at Museum für Naturkunde at the Humboldt University of Berlin were recognised as being quite distinct from other described hermit crabs. The family members differ from other hermit crabs in that their mandibles are chitinous and toothed.
Calcinus tubularis is a species of hermit crab. It is found in the Mediterranean Sea and around islands in the Atlantic Ocean, where it lives below the intertidal zone. Its carapace, eyestalks and claws are marked with numerous red spots. C. tubularis and its sister species, C. verrilli, are the only hermit crabs known to show sexual dimorphism in shell choice, with males using normal marine gastropod shells, while females use shells of gastropods in the family Vermetidae, which are attached to rocks or other hard substrates.
Around 1,300 species of freshwater crabs are distributed throughout the tropics and subtropics, divided among eight families. They show direct development and maternal care of a small number of offspring, in contrast to marine crabs, which release thousands of planktonic larvae. This limits the dispersal abilities of freshwater crabs, so they tend to be endemic to small areas. As a result, a large proportion are threatened with extinction.
Dardanus venosus, the starry-eyed crab or stareye crab, is a species of hermit crab in the family Diogenidae. It occurs in shallow water on the eastern coasts of America from Florida southward to Brazil. It is sometimes kept in reef aquaria.
The thinstripe hermit crab, Clibanarius vittatus, is a species of hermit crab in the family Diogenidae. It is found in the Caribbean Sea, the Gulf of Mexico and the western Atlantic Ocean.
Aniculus maximus, the hairy yellow hermit crab or large hairy hermit crab, is an aquatic hermit crab of the family Diogenidae.
Clithon corona is a species of brackish water and freshwater snail with an operculum, a nerite. It is an aquatic gastropod mollusk in the family Neritidae, the nerites.
Calcinus morgani, commonly known as Morgan's hermit crab, is a species of hermit crab in the family Diogenidae found in the Indo-West Pacific region, the type locality being Indonesia.
