Definition: aquatic organisms that construct and inhabit simple unbranched vertical shafts with only one opening to the surface. These are primarily above-sediment filter-feeders, surface deposit-feeders, and subsurface deposit-feeders (head-down, conveyor-belt feeders)
Definition: sediment that accumulates in the flat or very gently sloping areas of the deep ocean basin floor. The three main types are siliceous oozes, calcareous oozes, and red clays.