ABSTRACT. – The brine shrimp Artemia (Crustacea: Anostraca) is one of the most commonly used live preys in aquaculture. The quality of its cysts can vary from a strain to another and the study of its descriptors is of great importance for considering an eventual exploitation. Cysts and instar I nauplii of A. salina (Linnaeus, 1758) from Sebkha Ez-Zemoul have been characterized with regards to their biometry, hatching quality and fatty acid profile. The diameter of the cysts and the size of nauplii didn’t vary with the sampling periods of 2004 and 2006 (P > 0.05), and are respectively around 247 μm and between 460.43 ± 19.88 and 469.2 ± 34.3 μm. The chorion thickness is between 11.73 and 14.79 μm and the individual dry weight of nauplii is of 2.41 μg. Cysts harvested in water gave better results than those from the banks and the highest values of hatching percentage (57.93 %), efficiency (113,720 nauplii.g-1) and yield (0.239 g) were obtained after treatment of diapause deactivation with hydrogen peroxide. The hatching synchronization time is rather short and varied between 6 h and 8.83 h. Fatty acids analysis has shown that the percentage of unsaturated FAs was of 51.55 %. The only FA of the serial (n-3) was the linolenic acid LLA, 18:3n-3 with 6.43 %.