MAHON, H/K; DAUER, D/M; Old Dominion University: Particle Selection Dynamics of Surface Deposit Feeders: Roles of Particle Size, Organic Coating and Adaptive Morphologies

Surface deposit-feeding polychaetes rely on a poor food source for energy and nutrients. Many deposit feeders have evolved mechanisms, such as particle selectivity, to increase sediment processing efficiency and maximize net energy gain. This study examined the efficiency of particle selection by three surface deposit feeders with differing morphologies. Two tentaculate surface deposit feeders, Streblospio benedicti and Marenzelleria viridis were tested; one in the laboratory and one in the field. Both selected particles based on organic coating of the particle. Marenzelleria viridis showed selectivity for large particles over small particles. Particle selectivity of the non-tentaculate surface deposit feeder, Neanthes succinea, was tested in the laboratory and showed that it selected particles based on organic coating and based on size. However, there seemed to be a confounding effect between organic coating and size most likely due to the geometry of the particles for both M. viridis and N. succinea. Despite these complex results, our data show that microphagous surface deposit feeders can select for particles based on size and organic coating. This selection may be a mechanism to maximize net energy gain from a poor food source.