Feeding regulation by monoamines, neuropeptides and certain hormones has been studied in fish, but a possible role of melatonin is unknown. The purpose of the present study was to investigate the effects of melatonin on food intake in goldfish. Fishes were housed in 12L:12D and injected with different doses of either melatonin or 2-iodomelatonin. Two routes of administration, intracerebroventri...

Experiments were designed to determine the rate of gain of heat-tolerance for three different groups of goldfish, Carassius auratus, respectively acclimated to 4°C., 12°C., and 20°C., and subsequently moved to a temperature S°C. higher. The rate of change of heat-tolerance showed a marked difference in the three greups, twenty or more days being required for complete acclimation in the 40C. gro...