Socotra pseudocardisoma

Appearance

S. Pseudocardisoma has a dark carapace with a lightly colored margin. Males often have a purplish-black carapace bordered by a light brown margin, while females have a dark brown carapace with a light yellow margin. The legs are an earthy light yellowish orange, with a darker gradation around the articulations of the leg segments.

Range and habitat

S. Pseudocardisoma resides in holes, crevices and caves that occur in limestone outcrops of inland semi-arid uplands of Socotra Island in Yemen, particularly in the Diksam Plateau. Streams and pools can temporarily occur within the crevices and other features of the limestone, that are a likely water source for S. Pseudocardisoma. It is speculated that while S. Pseudocardisoma is found at elevations of 700 meters above sea level, it may be accessing water reserves that potentially exist deeper within the limestone.

Socotra pseudocardisoma (known colloquially as the Socotra karst crab) is a limestone dwelling species of terrestrial freshwater crab endemic to Socotra Island of Yemen. S. Pseudocardisoma has been observed in multiple locations at or above 700 m on the island of Socotra, however human developments, such as housing and livestock farms, and roads have contributed increasingly to habitat destruction and fragmentation.

Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.

Habits

Freshwater crayfishes and crabs walk the bed. Dams, silt, and introduced species cut a drainage into fragments they cannot cross.

Crayfishes and crabs need cover and clean water. A named form from one creek is not interchangeable with the next drainage.

In crisis

This species is marked as endangered and largely depleted according to the IUCN red list. Population numbers of S. Pseudocardisoma are thought to be decreasing, though the exact number of individuals currently alive is not known. It is dangerous for individuals to cross roads to connect with other subpopulations, limiting dispersal.

The species has also historically faced the threat of being hunted for food.

Socotra pseudocardisoma is Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.

Sources

Written for this catalog from the English Wikipedia article on Socotra pseudocardisoma, Wikidata item Q14362560. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.