Metabolic and digestive consequences of ongrowing greater amberjack (Seriola dumerili) juveniles at different temperatures

A good knowledge of the potential effects of water temperature on feeding and on-growing process is of primary importance to optimize the fish production. Temperature modulates ingestion, transit, digestion, assimilation, metabolism and ultimately feed utilization and growth rate. These two last parameters, together with the cost of feeds and energy, are necessary data for producers to make decisions. The production in indoor facilities with temperature control is depending on energy cost while in outdoor facilities (ponds and cages) it depends on environmental temperature. The effect of temperature is more noticeable in fast growing fish, as the greater amberjack (Seriola dumerili), a species of great interest for the aquaculture industry worldwide. Currently, its cultivation is expanding in the Mediterranean countries. Therefore, it constitutes a good model to study the consequences of an increased temperature. In this study, we examined the ingestion, digestive enzyme activities, metabolites in plasma and liver, antioxidant response in the liver and the integrity and electrogenic amino acid transport in the intestine, in greater amberjack juveniles growing at three different temperatures. The final aim was to elucidate the mechanisms behind feed utilization that justify the growth differences and to provide a useful informative basis to the productive sector.