The U.S. Fish and Wildlife Service has responsibility for threatened and endangered aquatic species in addition to the species they raise for mitigation and recovery in conservation hatcheries. These species, due to habitat degradation and loss, may need to be held in refugia. The success of such a program will require the determination of the nutritional needs of this species. For diet development and formulation it is important to know the elemental and proximate composition of the fish to be raised to help define the fish's requirements. For example, it has been determined that the lipid level and fatty acid composition of that lipid in the wild fish is important to know for diet development of fish species new to captive culture. Work done at Abernathy has demonstrated the importance of these feed components in the development of diets for the Lost River suckers and Pacific lamprey.