Different Temperature, Salinity Parthenogenesis Artemia Gahai Strain Survival, Reproduction, And The Intrinsic Ability To Grow

The survival rate and fecundity of Artemia parthenogenetica of Gahai Lake reared at five temperatures and under six salinity levels were reported in this paper. Nine life-tables were constructed at temperature of 15℃, 20℃, 25℃ and 30℃, and under salinity of 20‰, 100‰,140‰,180‰,220‰. Conclusions drew from the life-tables, life-span component and reproductive parameters were showed below.Artemia parthenogenetica of Gahai Lake can survive and have offspring when temperature ranged from 15℃ to 30℃ with salinity of 100‰. Population died before matured when temperature was 35℃. Maximum intrinsic rate of increase (rm), net reproductive rate (Ro), and the finite rate of increase (A,), and minimum generation time (T) was also achieved when temperature was 25℃. The strain had the longest life span and the greatest percentage of encysted offspring when temperature was 15℃. Differences were found for life span and reproductive parameters between populations reared at 15℃, 20℃, 25℃,30℃(P<0.01). With temperature decreasing, population would have a longer prereproductive period, reproductive period and period between broods.Artemia parthenogenetica of Gahai Lake can survive and have offspring when salinity ranged from 20‰ to 180‰. Maximum intrinsic rate of increase (rm), net reproductive rate (Ro), and the finite rate of increase (X), and minimum generation time (T) were achieved when salinity was 100‰. Population could not survive for more than two days under salinity of 260‰, and would die off in 53 days under salinity of 220‰. Salinity of 20‰ was not suitable for growth or maturity of this strain. When salinity ranged from 100‰ to 180‰, highly significant difference was found for four parameters: prereproductive period, offspring per female, offspring per brood per female, offspring per day per female.The results suggested that temperature could affect the parturition modes of Gahai strain. With temperature decreasing, higher percentage cysts produced. Population got the maximum percentage of encysted offspring (63.0%) when temperature was 15℃, and got the minimum percentage (4.8%) at 30℃. In the experiment of salinity group, population got the maximum percentage (22.2%) of encysted offspring when salinity was 140%o, and got smaller percentage under salinity of 100‰ (11.4%) and 180‰ (2.4%), When salinity was 20‰ and 220‰, all offspring were nauplii.