The effect of two different salinities on cyst biometry of Artemia urmiana from Urmia Lake regions Naseh Abdolah zadeh*1, Samad Zare1, Ramin Manaffar*2 and Alireza Asem3 1) Department of Biology, Faculty of Science, Urmia University, Urmia, Iran 2) Artemia and Aquatic Animals Research Institute, Urmia Uni, Urmia, Iran 3) Protectors of Urmia Lake National Park Society (NGO), Urmia, Iran Summary: Urmia Lake is one of the widest saline Lakes on world. It has no out let and restricted to almost 4000 km2 area in North West of Iran. A case way from the west to the east of the Lake now divided the Lake to two regions as North and West. Because of its salinity (200-300 ppt) Artemia is solely animal can tolerate this habitat for many years in the Lake and is the most famous animal in Aquaculture. Urmia Lake area by its wide rage of ecological conditions is known to have some Artemia populations that already were demonstrated in many papers using by molecular and morphological tools. These populations can produce cysts with different average size which is very important not only in aquaculture but also in marketing. To achievement the cause of this variability in cyst diameter, which is genetically or environmentally, in this project the cysts of Artemia were collected from 5 different regions of Urmia Lake from North and South. The cysts were hatched in optimum condition of hatching procedure. The hatched nauplii reared in 1 l conical tubes for 20 day by feeding of unicellular algae and Yeast according to optimum culture condition of Artemia in two different salinity of 75 and 150 ppt. 32 couple of adult Artemia from each populations (Artemia urmiana, bisexual) were carried out to the 50 ml falcon tubes (a tube for each couple) in corresponded salinity. The produced cysts from each population were collected every day of inside of falcon tubes by 150 micrometer sieves, for a period of 90 days. Finally the samples of cyst were hydrated in D&K solution for a period of 16 hour and 150 individual of each population were measured in diameter. The results and its statistic analysis in comparing with the original cyst collected from the Lake in table 1. Result and its statistically analysis revealed that, as well as previously released reports, the size of cyst in Urmia Lake is depend to culture conditions approximately, but according to the results of this study in some stations the salinity conditions not be able to influence the size of cysts comparing with original Lake cyst, in which shows the variability of cyst size is genetically, partially. In conclusion for farm culture of Artemia urmiana for cyst harvesting proposes, beyond to notice to the survival and total offspring factors of each population in farm culturing Artemia, the size of cyst that can be produced by each population already must be check empirically. Table 1: The cyst diameter originated from the Lake and produced in laboratory conditions in two salinities 75 and 150 ppt. Home