Alterations in lipid metabolism accompanying smoltification and seawater adaptation of salmonid fish

During the smoltification of salmonid fish, lipids are depleted from depot sites primarily from the triacylglycerol fraction. Increases in tissue lipolytic rates and decreases in rates of lipid synthesis are among the factors responsible for lipid depletion. Lipase mediated lipid depletion has also been observed following seawater exposure. Thyroxine, cortisol, growth hormone and prolactin underlie smoltification-associated lipid depletion and are probably involved in seawater-associated alterations in lipid metabolism.