Abstract
Aquarium experiments in the laboratory and a cage experiment on the sea bottom have shown S. tremulus (Gunnerus) to be selective in its feeding habits, selecting faecal pellets from benthic animals and other sediment aggregates, which are richer in organic content than the general surface sediment. Assimilation efficiency of organic material is close to 30 % but lower (17 %) during the spawning period. The species utilizes as nutriment about 2 % of the sediment consumed. An average animal consumes, annually, about 0.6 kg of sediment (dry weight) and the S. tremulus population at about 250 m depth in Raunefjorden, western Norway, reworks at least about 20 g of sediment per m2 per year.
