Stygobromus arizonensis

Stygobromus arizonensis, the Arizona cave amphipod, is a troglomorphic species of amphipod in family Crangonyctidae. It is endemic to Arizona in the United States.

It is known only from three specimens; two collected at a cave on the Flying "H" Ranch in 1963 and one from a mine near Paradise, Arizona. It has not been collected since then. The main threat to its survival is abstraction of groundwater.