Artemia are small aquatic crustaceans living in salt lakes and other saline waters which serve as experimental animals and foods to larval fish in aquaculture industry.Under unfavorable conditions,these animals can produce shelled embryos that suspend their development and metabolism at the gastrula stage and form cysts.When the environments become favorable,the cysts can resume their development and produce free-swimming larva within 24 hours.This protective process against adversities is shared by many organisms such as plant seeds,insects and even higher vertebrates,but its molecular bases are largely unknown.A well conserved response to stresses in all cell types investigated so far,from bacteria to mammals,is over expression of chaperones such as HSPs.p26,a member of chaperones with low molecular weights,was found abundant in the dormant embryos.By developing cDNA libraries of Artemia cysts at various developing stages and sequencing of randomly picked clones,we identified HSP90,HSP70,HSP40 and many other chaperones and calculated their relative abundance patterns in these cDNA libraries.In order to elucidate their potential implication on developing and dormancy of Artemia cysts,further investigations such Northern and Real-Time PCR analysis are needed.