Some factors influencing short-term food intake of the goldfish

Abstract

Goldfish press a lever in order to receive a food pellet during 1-hr sessions at the same time each day. They eat much less in 1 hr than when allowed to press the lever for a full day. The day-to-day 1-hr intake is stable. The intake in 1 hr is about the same when the fish have been deprived from 4 to 47 hr. This constancy cannot be accounted for by assuming a steady state in the gut. Four hours postfeeding virtually all undigested food from the previous feeding session remains in the gut; by 47 hr most or all has been excreted.