Phospholipid requirements have been established, for at least part of the life cycle for other freshwater omnivorous fish, such as the common carp, Cyprinus carpio (Geurden et al. 1998). Essential fatty acids are concentrated in the animal body primarily in PL in cell membranes, where they contribute to many of the characteristic properties of PL that affect the overall cell function. PL are the major lipid class in all biological membranes (Berg et al. 2002) and are vital to many physiological andbiochemical processes including nutrient digestion, absorption, and transport (Tocher et al. 2008).