K^+对中国明对虾幼虾生存及耗氧率、窒息点的影响

Effects of different K^+ concentrations on survival,oxygen consumption rate and suffocation point of juvenile Fenneropenaeus chinensis

采用单因子静态急性毒性实验方法,研究盐度为6的海水中不同K+浓度对中国明对虾(Fenneropenaeue chinensis)幼虾存活率的影响,并测定中国明对虾幼虾在不同K+浓度水质中的耗氧率及窒息点。结果表明:(1)K+含量过低或过高,均会成为影响中国明对虾幼虾生存的限制因子,中国明对虾幼虾对K+的生存适宜范围为16.00-165.80 mg/L,K+质量浓度低于16 mg/L时,中国明对虾幼虾的存活率随K+浓度的增加而上升;而当K+质量浓度高于165.80 mg/L时,中国明对虾的存活率随K+浓度的增加而下降。(2)水中不同K+浓度会对中国明对虾幼虾的耗氧率产生影响,在K+质量浓度分别为20 mg/L6、0 mg/L和120 mg/L,水温为(18.5±0.5)℃条件下,中国明对虾幼虾5 h平均耗氧率分别为(0.801±0.059)mg/g.h、(0.719±0.057)mg/g.h、(0.828±0.047)mg/g.h。(3)不论是低K+浓度组还是高K+浓度组,中国明对虾幼虾窒息点均明显高于正常海水K+浓度组,当水温为(19.4±0.1)℃,中国明对虾幼虾在K+质量浓度为20 mg/L、60 mg/L和120 mg/L时的窒息点分别为(1.469±0.006)mg(O2)/g、(1.350±0.005)mg(O2)/g、(1.496±0.006)mg(O2)/g。

Single-factor acute toxicity test was used and the oxygen consumption rate and suffocation point were measured to study the effect of the different potassium concentrations on survival and respiration of juvenile F. chinensis in seawater at salinity 6. The results indicated that juvenile F. chinensis could survive in seawater with K^＋ concentrations from 16.00 mg/L to 165.80 mg/L. When K^＋ concentration is below 16.00 mg/L,survival rate of F. chinensis increased with the increase of K^＋ concentration. When K^＋ concentration is over 165.80 mg/L, increase of K^＋ concentration could reduce the survival rate of juvenile F. chinensis. So K^＋ concentration of water is one of the limiting factors on survival of juvenile F. chinensis, and also affects their respiration. Compared with K^ ＋ concentration of normal seawater, the oxygen consumption rate and suffocation point of juvenile F. chinensis increased in both higher and lower K^＋ concentrations. When K^＋ concentrations were 20 mg/L, 60 mg/L and 120 mg/L, and temperature maintained at （ 18.5 ± 0.5） ℃, the average oxygen consumption rate of juvenile F. chinensis were （0. 801 ± 0.059） mg/ （g·h） ,（0.719 ± 0.057）mg/（g·h） and （0.828 ± 0.047）mg/（g·h） during the 5 h post exposure. When K^＋ concentrations were 20 mg/L, 60 mg/L and 120 rag/L, and water temperature maintained at （19.4 ± 0.1）℃, the suffocation point of juvenile F. chinensis were （ 1. 469 ± 0.006 ） nag （02）/g, （ 1. 350 ± 0. 005 ） rag（ O2 ）/g and （ 1. 496 ± 0.006 ） nag（ O2 ）/g. [Journal of Fishery Sciences of China, 2007,14 （3） ： 493 - 497 ]