-

The effects of different salinities on the survival, growth, reproductive and lifespan characteristics of three Artemia populations from Urmia lake, Maharlu lake and small lagoons around Urmia lake were studied in laboratory conditions. Artemia cysts were collected from the above-mentioned lakes and lagoons and hatched according to the standard proceduer. Four replicates of 200 newly hatched nauplii were treated in salinities of 75, 100, 125, 150 and 175 ppt. The larvae were fed with algae Dunaliella teriolecta and chemically treated yeast known as Lansy PZ. Survival rate of the Artemia were calculated on days 8, 11, 14, 17, 20 and 23 of growth. Total lenghts also were measuerd on days 8, 11, 17, 20 and 23 of growth using a micrometer and were compared with each other. After attaining the adulthood, thirty pairs of adult Artemia (in case of bisexual spp.) and 30 adult female (in case of parthenogenetic populations) were transferred from all salinities into separate 50 ml falcon tubes to compare their reproductive and lifespan characteristics. The results showed that survival and growth rates decreased with increasing salinity. Reproductive characteristics such as reproduction frequency, total offsprings, number of offsprings in each reproduction and number of offsprings in each day of reproduction period reduced with increasing in salinity. Moreover, higher salinity prolonged the pre-reproductive period but shortened the total reproductive period. Higher salinities also had some impacts on the percentage of encystment, postreproductive period and life span, but existence of a logic relationships between salinity and these parameters could not be proved.