温度与盐度对吉富品系尼罗罗非鱼仔鱼生长与存活的联合影响

摘要

We evaluated the effects of temperature and salinity on specific growth rate (SGR) and survival of Nile tilapia larvae (Oreochromis niloticus). We used response surface methodology (RSM) based on a two-factor Central Composite Rotatable Design (CCD) of experiments to optimize the level of these two factors within the range 18-37℃ and 0-16. The linear and quadratic effects of temperature and salinity had a significant effect on SGR and survival (P<0.05). Larval growth and survival increased then decreased with as temperature or salinity increased. In addition, the interaction between temperature and salinity had a significant effect on growth and survival (P<0.05). SGR and survival were higher at 18-20℃ between salinities 8 and 9 and at 27-32 ℃ between salinities 5 and 7. In contrast, SGR and survival were higher at ~salinity 4 at between 35-37 °C. The resulting formula was corrected for its coefficient of determination, yielding values of 0.979 6 and 0.982 1 (P<0.01), and had good predictive value. Temperature had a great influence on SGR than salinity, whereas the pattern was reversed for survival. Solving the regression equation for temperature equal to 29.TC and salinity equal to 5.4, the optimum predicted value for specific growth rate and survival is 10.08%-d-1 and 91.34%, respectively (value of desirability is 0.973). Thus, our data suggest the growth and survival of tilapia larvae can be improved by rearing the species at an optimal combination of temperature and salinity%采用中心复合实验设计(CCD)和响应曲面方法(response surface methodology,RSM),探讨了温度(18～37℃)和盐度(0～16)对吉富品系尼罗罗非鱼(Oreochromis miloticus)仔鱼生长和存活的联合影响.结果表明,本实验条件下,温度与盐度的一次与二次效应对特定生长率和存活率均有显著影响(P＜0.05),随着温度或盐度的上升,生长与存活均呈先上升后下降的变化.温度与盐度间存在互作效应(P＜0.05),温度为18～20℃时,仔鱼的特定生长率与存活率在盐度为8～9时较高；随着温度上升,27～32℃时,盐度为5～7时较高；高温环境时(35～37℃),盐度在4左右,生长与存活率较高.所考察因子与生长和存活率间的二次多项回归方程的决定系数分别达到0.979 6和0.982 l(P＜0.01),可用于预测罗非鱼的生长与存活率；温度效应对生长的影响较盐度明显,而对存活率的影响则相反.通过对所建立的两个回归方程同时优化,得到2个因子的最佳组合为:温度29.1℃和盐度5.4,在此最佳因子组合下罗非鱼仔鱼的特定生长率与存活率达到最优,分别为10.08％.d-1和91.34％,其可靠性达0.973.建议罗非鱼仔鱼在本研究中得到的最优因子组合下进行培育,以提高生产效率.