Spelaeorchestia koloana, the Kauai cave amphipod or in Hawaiian

Hawaiian language

The Hawaiian language is a Polynesian language that takes its name from Hawaii, the largest island in the tropical North Pacific archipelago where it developed. Hawaiian, along with English, is an official language of the state of Hawaii...

, is a cave-dwelling crustacean

Crustacean

Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...

 only found on the Hawaii

Hawaii

Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...

an island of Kauai

Kauai

Kauai or Kauai, known as Tauai in the ancient Kaua'i dialect, is geologically the oldest of the main Hawaiian Islands. With an area of , it is the fourth largest of the main islands in the Hawaiian archipelago, and the 21st largest island in the United States. Known also as the "Garden Isle",...

. It is eyeless and measures 7–10 mm (0.275590551181102–0.393700787401575 ) long. It is only known from five populations, and eats decaying plant matter and other decomposing material.

The Kauai cave amphipod is endemic to the caves on Kauai, Hawaii. Its main predator is the Kauai cave wolf spider Adelocosa anops

Adelocosa anops

The Kauai cave wolf spider , also known to local residents as the "blind spider", is only known to occur in a few caves in a lava flow with an area of in the Kōloa–Poipū region of Kauai, Hawaiian Islands, and only six populations are known to exist. While their nearest surface-dwelling relatives...

, another endemic of the Kauai cave. It is listed as an endangered species

Endangered species

An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...

 under the Endangered Species Act

Endangered Species Act

The Endangered Species Act of 1973 is one of the dozens of United States environmental laws passed in the 1970s. Signed into law by President Richard Nixon on December 28, 1973, it was designed to protect critically imperiled species from extinction as a "consequence of economic growth and...

, and on the IUCN Red List

IUCN Red List

The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...

.