''Stygobromus montanus'', commonly called Mountain cave amphipod, is a

troglomorphic Troglomorphism is the morphological adaptation of an animal to living in the constant darkness of caves, characterised by features such as loss of pigment, reduced eyesight or blindness, and frequently with attenuated bodies and/or appendages. The ...

species of

amphipod Amphipoda is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. Amphipods range in size from and are mostly detritivores or scavengers. There are more than 9,900 amphipod species so far descr ...

in family

Crangonyctidae Crangonyctidae is a family of cave-dwelling freshwater amphipod crustaceans. It contains the following genera: *'' Amurocrangonyx'' Sidorov & Holsinger, 2007 *'' Bactrurus'' Hay, 1902 *''Crangonyx ''Crangonyx'' is a genus of crusta ...

. It is endemic to Arkansas, in the United States.

References

Freshwater crustaceans of North America Cave crustaceans Crustaceans described in 1967 montanus Endemic fauna of Arkansas Endemic crustaceans of the United States {{Amphipod-stub