ABSTRACT
Inorganic elements or minerals constitute a relatively small amount of the total body tissues. However, they are essential for normal life processes of all animals, including fish. Fish require minerals in their diets, although they can absorb several mineral elements from the surrounding water to meet part of their metabolic requirements. Seven macrominerals (calcium, chlorine, mag nesium, phosphorus, potassium, sodium, and sulfur) and 16 trace minerals (aluminum, arsenic, chromium, cobalt, copper, fluorine, iodine, iron, manga nese, molybdenum, nickel, selenium, silicon, tin, vanadium, and zinc) have been shown as essential in one or more animal species (Davis and Gatlin 1996). However, not all of the minerals essential for warm-blooded animals have been found to be essential in the diet for fish. The physiological func tions of minerals are well defined for humans and some terrestrial animals, but this information for fish has not been well established.
