Final Thermal Preferendum of Atlantic Cod: Effect of Food Ration

Abstract
The spatial distribution of Atlantic cod Gadus morhua in the southern Gulf of St. Lawrence changed substantially between the 1970s and the 1980s. One proposed explanation for this phenomenon is that the fish were occupying different temperature zones as a result of changes in food availability brought about by changes in the species' abundance. To evaluate one key aspect of this hypothesis, we determined the final thermal preferendum of Atlantic cod in relation to food ration. After 6–15 weeks of conditioning to one of three predetermined rations, 72 fish 40–50 cm long were left to behaviorally thermoregulate three at a time in a horizontal thermal gradient for 45 h. Food ration produced significant differences among the condition indicators of the three groups. A small but significant difference (analysis of variance, P < 0.05) in final thermal preferendum was found between fish fed intermediate and low rations. Omission of the data from the first 3 weeks of the experiment, which showed signs of...

This publication has 30 references indexed in Scilit: