Hatchability of cysts and nutritional value of Artemia urmiana's nauplii in different incubation times were evaluated. The experiments were conducted at five incubation times 18, 20, 22, 24 and 26 hours, in triplicate random groups. Hatchability of cysts during these periods was determined with standard methods. Nauplii were hatched in five litre bottles to determine their biochemical composition. Dry weight, protein, lipid, carbohydrate, ash, caloric content and fatty acid compositions of naupiiies were determined at different developmental stages. Also, the dry weight and the biochemical composition of nauplii were determined individually, at different develop-mental stages. The results showed that the hatching percentage and efficiency increased with time with the hatching percentage being significant (P0.05). Based on the results, the incubation times 25 or 26 hours are recommended for harvesting nauplii. At these times, hatchability and the amount of harvested nauplii increased while their nutritional value was highest
