Off north-eastern Japan, the continental slope is rather narrow. It slopes steeply down to a depth of 1000m, but then forms a flat terrace between 1000 and 3000 m. Beyond 3000m the slope drops steeply down to the axis of the Japan Trench (7500m). Only one community type occurs in the upper bathyal zone (200–600m), an Ophiura association whose physiognomy is a “turf” of ophiuroids. The middle bathyal zone (600–1200m) is occupied by two types of community. The predominant community is an association characterized by an asteroid, Ceramaster, and a demersal fish, Sebastolobus, which has no characteristic physiognomy. The second is a comatulid community, which occurs on the shoulder of the slope as a comatulid “park”. The lower bathyal zones (1200–3000m) is inhabited by two distinct associations one of which has two facies. Most of the terrace area is occupied by an amphiurid association. In the plateau-like areas where there is a higher flow regime, there are sporadic, or sometimes rather dense stands of a coelenterate — the Radicipes facies. Whereas at the deeper site current are slower and the sediment is muddy, a Megayoldia — Ascorhynchus facies occurs in which a bivalve and a gigantic pycnogonid are found associated with amphiurids. The other community-type is a tubicolous-polychaete association which consists of a dominant polychaete species with a rather thin sandy tube which is associated always with a caprellid. This association is found on a shoulder-like topography, where bottom currents are expected to be constant and sediment is sandy. In the axis of the Japan Trench, where the sediment is soft mud, a small globular bivalve, Kelliella, is numerically dominant, which is associated with a holothurian, Elpidia, and a demersal fish, Careproctus. Nearby where the topography is a gentle slope, the community is typified by a dominant isopod, Storthyngura sp., accompanied by a bivalve, Spinula, and an actiniarian, Galatheanthemum.