This proposal plans to integrate two avenues of research that bear on our understanding of deposit - feeders, namely the clarification of the sedimentary food sources used by deposit feeders, and the development of the theoretical underpinning for explaining their foraging behavior. The specific objectives include: 1) clarifying the relationship of absorption rates of sedimentary organic matter and several of its important components, including microbes, microbal mucus, and adsorbed small molecules, in terms of feeding rates, gut turnover times, and absorption time constants; 2) determining the effects of body size and body shape on specific absorption rates and specific metabolic rates; and 3) determining the combined effects of intrinsic (size and shape related) and extrinsic (size related feeding position in the sediment) factors on the net energy gain during the developmental history of a head-down deposit feeder. The most significant aspect of the proposed research is that is integrates aspects of two exciting, but disparate, avenues of benthic research, one on the geochemical control of food availability, the other on an understanding of foraging behavior.
