尼罗罗非鱼选育二代盐碱耐受性和生长研究

Salinity-alkalinity Tolerance and Growth of Second Selected Generation of Oreochromis niloticus

在水温25℃左右条件下,将体质量50g左右的尼罗罗非鱼Oreochromis niloticus选育二代鱼种放入淡水水箱(0.6m×0.4m×0.5m)中进行致死试验,盐度和碱度从开始0g/L,每天分别提高8g/L和2g/L,直至鱼种全部死亡为止;另在养殖车间水泥池(6.0m×5.0m×1.6m)中放入选育二代鱼种,设置淡水组、盐度组(10g/L)、盐碱混合组[(10,2)g/L、(10,4)g/L和(10,6)g/L],分别用S0A0、S10A0、S10A2、S10A4和S10A6表示,研究其在不同盐碱环境中的生长,以评估选育二代的盐碱耐受性能和生长性能。慢性致死试验结果表明:选育二代与对照组(非选育群体)的半致死盐度分别为(57.37±1.56)g/L、(48.71±1.58)g/L,半致死碱度分别为(19.09±0.76)g/L、(16.32±0.45)g/L。60d的生长试验结果表明:在S0A0组中,选育二代日均增重率与对照组间差异不显著(P>0.05);在S10A0、S10A2、S10A4、S10A6组中,随着碱浓度的增加,选育二代与对照组日均增重率下降,选育二代日均增重率均显著大于对照组(P<0.05)。本研究结果表明:选育后代的盐碱耐受性能和盐碱环境下的生长性能均有明显提高。

Chronic salinity-alkalinity lethal test was in a tank of 0.6 m × 0.4 m × 0.5 m in the water with elevated salinity flom 0 g/L to the lethal salinity in an increasing 8 g/L salinity and 2 g/L alkalinity interval a day and 60 days growth trail were carried out cement tanks of each 6.0 m × 5.0 m × 1.6 m in second selected generation of juvenile Oreochromis niloticus with body weight of some 50 g reared in flesh water （SOA0 group）, salinity group （ 10 g/L, S 10A0 group） and different salinity-alkalinity waters [（ 10, 2 ） g/L, S 10A2 group; （ 10, 4） g/L, S10A4 group; and （ 10, 6） g/L, S10A6 group] in order to assess salinity-alkalinity tolerance and growth perfor- mance of the second selected generation o f Oreochromis nilotic us. It was found that the median lethal salinity was （ 57.37 ±1.56 ） g/L in the second selected generation, and （48.71 ± 1.58） g/L in the control group, and that the median lethal alkalinity was （ 19.09± 0.76 ） g/L in the second selected generation group and （ 16.32± 0.45 ） g/L in the control group. The growth comparison showed that there was no significant difference in average growth rate between the SOA0 group and the control group （P 〉 0.05 ）. However, the ave- rage growth rate was shown to be decreased in S 10A0, S 10A2, S 10A4 and S 10A6 groups with the elevation of alkalinity, significantly different in the second selected generation group than the fish in the control group （P 〈 0.05 ）, indicating that the selected generation of Oreochromis niloticus showed high salinity-alkalinity tolerance and good growth performance.