钠、钾离子浓度及比例对鳗鲡早期发育的影响

Effects of Na+, K+ concentrations and Na+/K+ ratio on early development of Anguilla japonica

摘要:

研究了不同Na⁺和K⁺含量以及Na⁺/K⁺值(R值)的人工海水对鳗鲡受精卵孵化率、仔鱼畸形率及存活时间的影响。实验共分3组:(1)保持Na⁺含量正常,改变K⁺含量;(2)保持K⁺含量正常,改变Na⁺含量;(3)稳定Na⁺/K⁺=28,调整Na⁺、K⁺含量。结果发现:当保持Na⁺浓度稳定,K⁺浓度为538 mg/L时,鳗鲡受精卵的孵化率最高(44.0%),畸形率最低(23.8%),仔鱼的存活时间最长;当Na⁺/K⁺=28、Na⁺和K⁺的绝对含量分别为8400、300 mg/L时,孵化率最高。较高的Na⁺(19500 mg/L)、K⁺浓度(1076 mg/L)将会导致鳗鲡受精卵孵化率降低,但对仔鱼畸形率的影响并不显著。结果表明,鳗鲡受精卵孵化以及仔鱼培育所用人工海水需按Na⁺和K⁺含量及R值做相应调配,最适Na⁺、K⁺浓度分别为7800~11700 mg/L和360~540 mg/L,R值在20~30之间。

Abstract:

Impacts of different Na⁺ and K⁺ concentrations and Na⁺/K⁺ ratios on the hatching rate of fertilized eggs, deformity rate of newly hatched larvae and survival time of larvae of Anguilla japonica were studied in this paper. There were three experiments1) maintaining normal Na⁺ concentrations, while changing the concentration of K⁺; 2) maintaining normal K⁺ concentrations, while changing the concentration of Na⁺; and 3) maintaining stable Na⁺/K⁺ at 28, while changing both Na⁺ and K⁺ concentrations. The results showed thatWhen the concentration of K⁺ was 538 mg/L and Na⁺ 10760 mg/L, the highest hatching rate (44.0%) and the lowest deformity rate (23.8%) as well as the longest survival time were achieved. When Na⁺ to K⁺ ratio maintained at 28, with Na⁺ and K⁺ concentrations at 8400 mg/L and 300 mg/L respectively, the hatching rate was the highest among the five groups. Hatching rates would decline if the concentrations of Na⁺, K⁺ were too high (19500 mg/L and 1076 mg/L respectively). These results indicated that appropriate Na⁺, K⁺ concentrations and R values are required with optimum Na⁺, K⁺ concentrations varying between 7800-11700 mg/L and 360-540 mg/L respectively and R values 20-30.