Feeding of Juvenile Coho Salmon (Oncorhynchus kisutch): Maximum Appetite, Sustained Feeding Rate, Appetite Return, and Body Size

Abstract

Experimental investigations of the influence of body size and feeding rate on the voluntary consumption of live Tubifex by juvenile coho salmon (Oncorhynchus kisutch) showed that maximum appetite and sustained feeding rate increased allometrically with coho body size. There was no significant effect of body size on the rate of appetite return following a meal, although a comparison of these results with data from the literature suggests that the rate constant of appetite return may decrease with body size. The rate constant of appetite return following meals preceded by 96 h of starvation was significantly greater than that for meals preceded by 3–5 d of satiation feeding. If the latter effect also applies to the rate constant of gastric evacuation for live foods, the use of standard gastric evacuation models could overestimate the rate of food intake of wild fish feeding at close to their maximum rate.