Time-Dependent Absorption in Deposit Feeders

* Final gross prices may vary according to local VAT.

Get Access

Abstract

Deposit feeders obtain food from sediments consisting mostly of indigestible mineral grains. In order to procure the required energy and nutrients, these animals must process enormous quantities of sediment (Canunen 1980b). The necessarily rapid processing rates limit the amount of time material may remain in the gut. Many deposit feeders have gut residence times of 30 minutes or less. Juvenile Streblospio benedirti can have gut residence times as low as 4 minutes (T. Forbes, pers. com.). Since digestion is a time-dependent process, gut residence time is likely to control absorption of ingested food, particularly when the food is difficult to digest. While the amount of material absorbed will increase with increasing gut residence time, it is likely to do so at a reducing rate (Sibly and Calow 1986). Therefore there will be a tradeoff between the efficiency and speed of digestion.