Abstract
Burrows of the Japanese crayfish Cambaroides japonicus (DE HAAN, 1841) in a stream in Sapporo, Hokkaido are described. The density of number of openings averaged 4.5/m^2 in ten reserch stations around the banks. The diameters of dominant particles were 0.125-0.400 mm at the central part of stations. Six resin casts of burrows showed that this species excavated a semistraight tunnel with two openings near the water surface of the stream. This tunnel was almost horizontal and was semicylindrical in cross-section with the floor flat. Some were also observed Y or T shaped burrows.
