5.1 Measurement of Stomach Contents
The most common method of determining gastric evacuation time and the digestive action of the stomach has been serial slaughter. This involves feeding a population of fish to a specified level (usually a percentage of body weight), then killing portions of the population at various times afterwards and analyzing the remaining stomach contents (analytic methods discussed below). Problems involved in this method include the variability of food intake by different individuals and the stress imposed on the population by capturing sub-samples: chasing and fright would be expected to inhibit digestion.