''Mictocaris halope'' is the only species of cave

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 ...

in the monotypic genus ''Mictocaris''. It is placed in its own family, Mictocarididae, and is sometimes considered the only member of the order

Mictacea Mictacea is a monotypic order of crustaceans. It was originally erected for three species of small shrimp-like animals of the deep sea and anchialine caves. They were placed in two families, the Mictocarididae and Hirsutiidae, but Hirsutiidae ...

. ''Mictocaris'' is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

to anchialine

cave A cave or cavern is a natural void in the ground, specifically a space large enough for a human to enter. Caves often form by the weathering of rock and often extend deep underground. The word ''cave'' can refer to smaller openings such as sea ...

s in

Bermuda ) , anthem = "God Save the King" , song_type = National song , song = "Hail to Bermuda" , image_map = , map_caption = , image_map2 = , mapsize2 = , map_caption2 = , subdivision_type = Sovereign state , subdivision_name = , es ...

, and grows up to long. Its biology is poorly known.

Taxonomy

''Mictocaris halope'' is the only species in the genus ''Mictocaris'', and in the family Mictocarididae. When the family

Hirsutiidae Hirsutiidae is a family of 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 an ...

is treated as the separate order Bochusacea, ''Mictocaris halope'' is the only species that remains in the order

Description

''Mictocaris'' is long and is reflective. It is native to four anchialine

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

caves in Bermuda: it was first discovered by divers in Crystal Cave, and then further populations were found in Green Bay Cave (South Harrington Sound Passage and North Shore Passage), Roadside Cave and Tucker's Town Cave.

Ecology

''Mictocaris'' is rarely encountered because it lives only in deep waters in the interior sections of the caves. It avoids sunlight and remains in isolated parts of the cave. It is usually seen swimming, but on rare occasions can be found resting or walking on a rock. When relocated into an aquarium, they prefer the walls and surfaces of the glass. It is unknown what ''Mictocaris'' eats, but it has developed powerful molar and mandible muscles which allows them to chew productively. When originally found, the divers collected 56 specimens of ''Mictocaris'', which can now be found in the

National Museum of Natural History The National Museum of Natural History is a natural history museum administered by the Smithsonian Institution, located on the National Mall in Washington, D.C., United States. It has free admission and is open 364 days a year. In 2021, with 7 ...

Conservation

''Mictocaris'' is critically endangered due to

population fragmentation Population fragmentation is a form of population segregation. It is often caused by habitat fragmentation. Causes of Fragmentation Fragmentation can be the cause of natural forces or human actions, although in modern times, human activity is th ...

, a decline in subpopulations, and only inhabiting a single location. The population is only extant in five locations, some of which are likely experiencing habitat destruction.

References

{{Taxonbar, from=Q5487648 Malacostraca genera Freshwater crustaceans of North America Endemic fauna of Bermuda Taxonomy articles created by Polbot