Abstract:Influences of different NaCl salinity (0, 1, 3, 5, 7, 9) and NaHCO3 alkalinity (1.00 mmol/L, 10.00 mmol/L, 15.85 mmol/L, 25.12 mmol/L, 39.81 mmol/L, 63.10 mmol/L) on hatching rate, deformity rate of the embryos, and 24, 48h survival rate of newly hatched larvae of Songpu mirror carp (Cynipus carpio) and gibel carp (Carassius auratus gibelio) were investigated in this study. The significant differences between the results and salinity or alkalinity were analysed with Duncan’s multuple comparison by using SPSS 17.0 software. ① The results of the experiments about salinity showed that the high hatching rates of Songpu mirror carp were observed when the salinity ranged from 0 to 1, which was 72.40% ± 6.09% on average. The deformity rates of Songpu mirror carp were lower obviously at salinities 0 to 3 than other groups, and the mean deformity rate was 6.02% ± 1.87%, meanwhile, the mean 48h survival rate was 94.99% ± 6.44%. For Gibel carp, high hatching rates were observed at salinities from 0 to 3, which was 68.03% ± 15.44% on average. The deformity rates of Gibel carp were low obviously at salinities 0 to 5, and the mean deformity rate was 7.95% ± 3.24%, meanwhile, the mean 48 h survival rate reached 88.52% ± 9.19% (Fig.1). ② The results of the experiments about alkalinity showed that the high hatching rate of these two fishes were observed when the alkalinity ranged from 1.00 to 25.12 mmol/L, and it was 47.96% ± 8.43% for Songpu mirror carp and 66.23% ± 18.11% for Gibel carp on average. The deformity rates of these two fishes were lower significantly when the alkalinity ranged from 1 to 15.85 mmol/L, and it was 12.47% ± 3.77% for Songpu mirror carp and 12.46% ± 8.44% for Gibel carp on average. When the alkalinity ranged from 1 to 15.85 mmol/L, the mean 48h survival rate of Songpu mirror carp was 96.16% ± 5.04%, and the mean 48h survival rate of Gibel carp was 85.62% ± 3.73% (Fig.2). In conclusion, for Songpu mirror carp and gibel carp, the suitable salinity for the hatch of fertilized eggs and the survival of larvae should be lower than 3, and the suitable alkalinity should be lower than 15 mmol/L.
