Measurement method of the underground water level in habitats of Japanese crayfish Cambaroides japonicus

Abstract

The underground water level which shows annual changes is a potential factor restricting the habitat of the endangered Japanese crayfish, Cambaroides japonicus (De Haan, 1841) However, this factor in habitats of Japanese crayfish has not been previously monitored. We introduce an adapted method to measure the underground water level (hyporheic zone) in the streambed of brooks, and discuss the influence of this factor on the habitat use by Japanese crayfish.