Effect of food attractants on appetite and growth rate of gilthead bream, Sparus aurata L.

Appetite and growth rate were measured in Sparus aurata fed ad‐libitum a basal diet supplemented with either a synthetic mixture of chemicals based upon the analysis of Mylilus edulis, muscle extract, or newly hatched Artemia saline nauplii. These components were tested for their feeding attraction potency, and were added to the basal diet at three concentrations each; 5, 10 and 20 g kg^‐1 dry diet. Appetite, which was defined as ad‐libitum food intake, was significantly affected by the type and concentration of attractant. When the basal diet was supplemented with 10 or 20 g kg^‐1 of the synthetic Mytilus edulis muscle extract, it was associated with significantly higher appetite than the basal diet only or the basal diet supplemented with any level of newly hatched Artemia salina nauplii. On the other hand, relative growth rate under the same conditions did not completely conform to the results with appetite. The difference between appetite and growth rate as criteria for the evaluation of food attractants is discussed.