Sillago siharna (FBrskal) egg diameter varies with stage of development, age of spawner, water temperature, salinity, and timing of spawning season. Among these factors, spawner age, water temperature and salinity seem to be the most important. Three-month-old fish produced smaller eggs than l-year-old fish. The size of released eggs tended to decrease with increasing water temperature. Above 28.7 "C, more than 50 % of the eggs contained multiple oil globules. Salinity decrease causes the production of larger and more buoyant eggs.