The conservation status of a group of organisms indicates whether the group still exists and how likely the group is to become extinct in the near future. Many factors are taken into account when assessing conservation status: not simply the number of individuals remaining, but the overall increase or decrease in the population over time, breeding success rates, and known threats. Various systems of conservation status are in use at international, multi-country, national and local levels, as well as for consumer use such as sustainable seafood advisory lists and certification. The two international systems are by the International Union for Conservation of Nature (IUCN) and The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).
A species that is extinct in the wild (EW) is one that has been categorized by the International Union for Conservation of Nature as only consisting of living members kept in captivity or as a naturalized population outside its historic range. Classification requires exhaustive surveys conducted within the species' known habitat with consideration given to seasonality, time of day, and life cycle. Once a species is classified as EW, the only way for it to be downgraded is through reintroduction.
Protocobitis typhlops is a species of troglobitic loach endemic to Guangxi, China.
The West Virginia spring salamander is a species of troglobitic salamander in the family Plethodontidae. It is endemic to West Virginia, the United States.
Speleoperipatus is a monospecific genus of velvet worm in the Peripatidae family, containing the single species Speleoperipatus spelaeus. This species is a pale greenish yellow, almost white, with 22 or 23 pairs of legs and no eyes. Specimens range from 27 mm to 34 mm in length. The minimum number of leg pairs found in this species (22) is also the minimum number found in the neotropical Peripatidae. This velvet worm is viviparous, with mothers supplying nourishment to their embryos through a placenta.
Allocrangonyx is a genus of troglobitic amphipod crustaceans from the South Central United States. The two species are both listed as vulnerable on the IUCN Red List. The animals are blind and unpigmented. During the male's development, the outer ramus of the third uropod differentiates into secondary segments and grows to a length greater than the animal's body length.
Astacoides is a genus of freshwater crayfish endemic to Madagascar. The first specimens were brought to Europe in 1839, and seven species are now recognised, most of which are considered as threatened on the IUCN Red List. They are large and slow-growing, and are threatened by habitat loss, overexploitation by local people and by spread of introduced non-indigenous marbled crayfish. They are only found in a relatively small part of the island, mostly in undisturbed upland areas. They belong to the Gondwana-distributed family Parastacidae, but their nearest relatives live in Australasia, there being no native crayfish in mainland Africa or India.
Crangonyx dearolfi, also known as the Pennsylvania cave amphipod or Pennsylvania cave crangonyctid, is a species of crustacean in the family Crangonyctidae. It is native to the United States, where it is found in caves in Pennsylvania and Maryland.
Crangonyx is a genus of crustacean in family Crangonyctidae. Crangonyx species can live in marshes, savannas or swamps as well as caves. It contains the following species:
Crangonyx grandimanus is a species of crustacean in family Crangonyctidae. It is endemic to the United States.
Erebonectes is a genus of crustaceans in the family Epacteriscidae, containing two troglobitic species. E. nasioticus was discovered in Bermuda and described in 1985; it is listed as critically endangered on the IUCN Red List. E. macrochaetus was found on Middle Caicos and described in 1994.
Lirceus usdagalun is a rare species of crustacean known by the common name Lee County cave isopod. It is endemic to Virginia in the United States, where it is known from a single network of karst cave systems in Lee County. It is threatened by a number of processes. It is a federally listed endangered species of the United States, and is assessed as "endangered" by the International Union for Conservation of Nature.
Troglocambarus is a monotypic genus of troglobitic crayfish, endemic to Florida. Troglocambarus maclanei is found underground in Hernando, Marion, Alachua, Columbia, Gilchrist and Suwanee counties, and is named after Mr. William A. McLane who first collected it. It is commonly called the North Florida Spider Cave crayfish.
Astacoides hobbsi is a species of southern crawfish in the family Parastacidae.
Procambarus lucifugus lucifugus, known as the Withlocoochee light-fleeing cave crayfish, is one of two subspecies of the vampire crayfish, along with Procambarus lucifugus alachua. It is distinct from P. l. alachua due its lack of eyespots. Intergrades of the two P. lucifugus subspecies, P. l. alachua as well as P. erythrops and P. leitheuseri have been found to have little genetic differentiation, especially when compared to P. l. lucifugus which is distinct from all of those. It has been suggested that P. l. lucifugus may prove to be a different species, found only in two freshwater caves, the location of one of which is unknown.
The Malabar swamp eel is a species of troglobitic swamp eel endemic to subterranean springs in Kottayam in the Indian state of Kerala.
Cambarus jonesi, the Alabama cave crayfish, is a small, freshwater crayfish endemic to Alabama in the United States. It is an underground species known only from 12 caves.
Procambarus lucifugus alachua, known as the Alachua light-fleeing cave crayfish, is one of two subspecies of the vampire crayfish, along with Procambarus lucifugus lucifugus. It is distinct from P. l. lucifugus due its eyespots.
