钾和镁离子对大西洋鲑卵孵化及仔鱼开口的影响

Effects of Potassium and Magnesium on Egg Hatchin and First Feeding of Atlantic Salmon(Salmo salar)Larvae

地下水是大西洋鲑(Salmo salar)早期发育的首选水源,为确定在地下水中K`+、Mg^(2+)的适合添加剂量。本文对预选鲑鳟鱼孵化基地的地下水水质进行分析,发现其K^+、Mg^(2+)含量偏低,可能不利于大西洋鲑孵化。采用完全正交设计,研究了在该地下水中添加K+、Mg^(2+)两种离子对大西洋鲑卵的存活、孵化及仔鱼开口的影响。研究表明,Mg^(2+)在大西洋鲑早期发育阶段扮演着重要角色,在地下水中添加5 mg/L Mg^(2+),能显著提高鱼卵存活率(P <0.05)和仔鱼开口率(P<0.05)。K^+添加至8mg/L时不利于鱼卵生存(P<0.05),K^+对大西洋鲑仔鱼的开口影响不明显(P>0.05)。K+与Mg^(2+)同时添加对大西洋鲑仔鱼的开口率交互影响显著(P<0.05)。水中K^+添加量达到8mg/L时,添加10mg/L Mg^(2+)对大西洋鲑卵的存活、孵化及仔鱼开口产生消极影响。研究结果表明,大西洋鲑早期发育水体中K^+含量应低于9mg/L,Mg^(2+)含量应控制在15.54mg/L左右。

China has developed the program of culturing Atlantic salmon(Salmo salar)in the Cold Water Mass of Yellow Sea.Previous analysis has showed that the underground water had low concentrations of potassium and magnesium,which affect the hatching of S.salar eggs.Therefore,this study was carried out,aiming to determine the effects of potassium and magnesium at different concerntations on survival and hatching of S.salar eggs,and the first feeding of larvae in order to provide high-quality fry to the industry.The results showed that magnesium played an important role in the early development of S.salar.Adding 5 mg/L magnesium into the groundwater apparently increased the survival rate of S.salar eggs(P<0.05)and the first feeding rate of S.salar larvae(P<0.05).Adding 8 mg/L potassium was not favorable for salmon survival(P<0.05).Although the effect of potassium on the first feeding of S.salar larvae was not significant(P >0.05),the interaction of potassium and magnesium on the first feeding rate of S.salar larvae was significant(P<0.05).Adding 8 mg/L potassium and 10 mg/L magnesium negatively affected the survival and hatching of S.salar eggs and the first feeding time of S.salar larvae.Therefore,the potassium should be added no higher than 9 mg/L and the magnesium should be kept at 15.54 mg/L for a better early development of S.salar.