EFFECT OF TEMPERATURE ON LOCOMOTOR-ACTIVITY IN THE GOLDFISH (CARASSIUS-AURATUS) AND THE BLUEGILL (LEPOMIS-MACROCHIRUS) - PRESENCE OF AN ACTIVITY WELL IN THE REGION OF THE FINAL PREFERENDUM

Goldfish (Carassius auratus) and bluegill sunfish (Lepomis macrochirus) were placed in aquaria where their locomotor activity was monitored by photocells, and tested at various acclimation temperatures over a range encompassing their final thermal preferenda. Activity was pooled over 24-hour periods to eliminate any circadian rhythm effects. Both species exhibited an 'activity well' of reduced locomotor activity in the region of the final preferendum. Goldfish, tested either singly or in groups of 2-5 individuals, exhibited a social-interaction effect which became more pronounced at higher temperatures. These results are discussed in relation to a thermokinetic interpretation of thermo-regulatory behavior in fishes, and to the correspondence between thermal preferenda and thermal optima. © 1979 Dr. W. Junk b. v. Publishers.