Minerals are essential inorganic nutrients required by aquatic animals in small but vital quantities for maintaining normal physiological functions, growth, reproduction, and overall health. Unlike terrestrial animals, aquatic organisms can absorb certain minerals directly from water through gills, skin, and digestive surfaces, in addition to dietary intake. Nevertheless, a balanced mineral supply through feed and water is necessary to prevent deficiencies and ensure optimal aquaculture production. Macrominerals such as calcium, phosphorus, magnesium, sodium, potassium, and chloride are required in relatively large amounts. Calcium plays a central role in the formation of bones, scales, shells, and exoskeletons, and is also important for muscle contraction, blood clotting, and nerve transmission. In crustaceans, calcium is particularly crucial for molting and hardening of the exoskeleton. Phosphorus works closely with calcium in skeletal development and is a key component of nucleic acids, phospholipids, and energy molecules like ATP. A deficiency of phosphorus can lead to poor growth, skeletal deformities, and reduced feed efficiency. Magnesium functions as an activator of many enzymes and contributes to muscle function and protein synthesis.