EFFECTS OF BROWSING PREDATORS: ACTIVITY CHANGES IN INFAUNA FOLLOWING TISSUE LOSS

¹ Department of Biology and Belle W. Baruch Institute of Marine Biology and Coastal Research, University of South Carolina, Columbia, South Carolina 29208

Effects of tissue loss on defecation and/or tube building are documented for three infaunal species of polychaete annelids, Abarenicola pacifica, Axiothella rubrocincta, and Spiophanes bombyx. Abarenicola and Axiothella feed head down and expose their tails while defecating; their tail tips were experimentally ablated. Spiophanes feeds on the sediment surface with its pair of tentacles and its head. One or both of its tentacles were experimentally removed. The tissues removed in the experiments are those often lost to browsing predators in field populations. Defecation frequency and amount were significantly reduced in the experimental individuals relative to controls in all three species. In Spiophanes tube building was also significantly reduced; in Axiothella it was not. These results indicate that rates of biogenic sediment modification can be strongly affected by tissue losses of infauna to browsing predators.