Ingestion rate: An empirical model for aquatic deposit feeders and detritivores

Published ingestion rates of total dry material (inorganic and organic) by benthic invertebrate deposit feeders and detritivores feeding at 15°C could be explained almost entirely by organic content of the ingested material and body size; the relation was consistent for 19 species from 3 phyla. Since ingestion rate of total dry material varied inversely with the organic content of the food, organic matter ingestion (C) was essentially a function of body size (W): $$C = 0.381 \cdot W^{0.742} $$ where C is mg day^-1 and W is mg dry weight. These animals may maintain a rate of intake of organic matter which is independent of the organic content of the food source by: (1) Actively adjusting their feeding rates according to some perception of food “quality”, and/or (2) Adapting their feeding rates to different environments on an evolutionary time scale.