Inter-comparison of some equations for evaluating fish daily ration by numerical experiment with an impulse-input feeding model

The rate of food ingestion by fish in an impulse-input type model is repres ented as a unit impulse or Dirac delta function. It is assumed that dependi ng on the of food type, the stomach]las;a limited capacity. Maximal meal si ze is equal to the difference between the maximum stomach capacity and the food containing within, at any given feeding time. The content of the stoma ch of a single fish during 20 days is simulated by the impulse-input feedin g model. Feeding frequency and meal size are randomly generated, while an e xponential model describes gastric evacuation. Daily ration is determined f rom food quantities in the stomach at time intervals of 2, 3, 4 and 6 h, wi th five well-known food consumption equations. Lowest errors were shown by the Elliott and Persson equation and the second Eggers equation. The first Eggers equation showed the highest error. The first Eggers equation was ass ociated with differences between the content of the stomach at the end and beginning of the sampling period (0-24 h). (C) 2001 Elsevier Science B.V. A ll rights reserved.