Influence of adult density on recruitment into soft sediments: A short-term in situ sublittoral experimental

Effects of different densities of the ophiuroid Amphiura filiformis and of the bivalve Abra nitida (both species separately) on initial recruitment were studied in situ in a soft-sediment environment at 25 m depth in the Gullmar Fjord (Sweden). Containers with known densities of resident in natural sediment, and some defaunated controls, were exposed for 9 d on the bottom. With both species there was a clear effect on both density and horizontal spatial distribution of recruits in the experimental containers. It is suggested that A. filiformis may inhibit recruitment by ingesting settlers or newly settled juveniles.