Predicting particle selection by deposit feeders: A model and its implications 1

Abstract

A feeding model for a generalized, benthic deposit feeder is derived from a filter-feeding model and used to predict how such a deposit feeder would adjust its feeding to maximize its net energy gain. Under the assumption that deposit feeders are utilizing the bacterial fraction of the sediment or other surface organic coatings as food, the model predicts that the smallest particles should always be ingested, while the selection of larger particles depends on several parameters, including gut passage time and assimilation efficiency of the deposit feeder. The model also predicts relationships among particle size selection, assimilation efficiency, gut passage time, gut volume, and particle rejection costs.

Ingestion rate of a selective deposit feeder in a complex mixture of particles: Testing the energy‐optimization hypothesis1

“…They have not shown that the composition variable R has anything to do with nutritional value, however. If we assume, like Taghon et al (1978), that deposit feeders digest the microbiota on the surface of particles, the most meaningful nutritional parameter ought to be the surface:volume ratio of the ingested material. In these experiments, the animal could not be persuaded to ingest a sediment consisting entirely of glass spheres without added floc, and the surface: volume ratio of the latter is unknown.…”

“…Lehman (1976) and Lam and Frost (1976) have proposed models of planktonic filter feeding that depend heavily on the assumption that feeding behavior maximizes the net energy gain to the anirnal. Taghon et al (1978) have successfully adapted Lehman's model to deposit feeders. If these models are to have any predictive value, energetic considerations must be dominant over all the other selection pressures that might conceivably have shaped the morphology and behavior associated with feeding.…”

“…Taghon et al (1978) have successfully adapted Lehman's model to deposit feeders. If these models are to have any predictive value, energetic considerations must be dominant over all the other selection pressures that might conceivably have shaped the morphology and behavior associated with feeding.…”

“…The problem of testing the energy-maximization hypothesis reduces to the problem of discovering whether the parameters of one or more of the mechanistic feeding models optimize the energy budget in the laboratory or in nature. Or, as Taghon et al (1978) more correctly phrased the problem: how to prove that these parameters do not maximize the energy gain. This is not a matter of disproving the mechanistic models, which are known to fit the data pretty well and to be difficult to distinguish from one another statistically (Mullin et al 1975), but of disproving the assumption that the parameters of the models (or model) are predictable from energy budget considerations.…”

Ecological Determinants of Spionid Distributions Within Dense Patches of Deposit-Feeding Polychaete Axiothella rubrocincta

“…This particulate material consists of an amorphous organic matrix surrounding clay and silt-sized mineral particles (< 88 pn) (see Zabawa, 1978, for a description of the physical properties of OMA). OMA are considered to be an important food resource to deposit feeders due to their high organic content (Johnson, 1974) and bacterial, meiofaunal, and microfloral associates (Hargrave, 1972;Taghon et al, 1978). OMA are major constituents of surficial sediments from the intertidal zone to depths of 5000 m (Johnson, 1977).…”