Rate of food evacuation in roach (Rutilus rutilus) in relation to temperature, and the application of evacuation rate estimates for studies on the rate of food consumption

SUMMARY. Food evacuation in roach (total body length, range 75–150 mm) was studied at temperatures between 4.2 and 24.0 °C. The rate of food evacuation was described by an exponential function and was similar for two different food items ( Daphnia and Chaoborus ). The relation between the instantaneous rate of food evacuation ( R ) and temperature was also described by an exponential function. A model developed for estimating food consumption rates in fish was tested in a simulation experiment and there was good agreement between estimated and actual values for food consumption.