急性盐度胁迫对三疣梭子蟹(Portunus trituberculatus)“黄选1号”血清渗透压及离子含量的影响

Effects of Abrupt Salinity Stress on Serum Osmolarity and Ion Concentration of “Huangxuan No.1” Portunus trituberculatus

为探索三疣梭子蟹(Portunus trituberculatus)"黄选1号"在盐度适应过程中血清渗透压和离子浓度的变化特点及规律,进而了解其渗透压调节机理,设置盐度为5、10、20和50共4个实验组,以盐度30的自然海水为对照组,进行三疣梭子蟹"黄选1号"急性盐度胁迫实验。结果显示,各实验组血清渗透压呈规律性变化,0–12 h期间,低盐实验组血清渗透压较对照组表现为下降,盐度为50的高盐实验组,血清渗透压表现为上升;12–72 h期间,各实验组血清渗透压达到稳定状态。随着胁迫盐度的升高,血清与环境介质渗透压的差值先减小后稳定,与外界环境未出现等渗现象。血清中Cl^-、Na^+、K^+含量的变化与血清渗透压的变化相似,但血清与环境介质离子含量的差值表现为Cl^-、Na^+含量差值先下降后稳定,K^+含量差值表现为先上升再下降最后稳定。研究表明,三疣梭子蟹"黄选1号"渗透压调节类型属于高渗调节型,Cl^-和Na^+在渗透压调节中起主要作用,提示三疣梭子蟹"黄选1号"具有较强的渗透压调节能力,对生存环境盐度的变化具有较强的适应能力。

In this study we exerted acute salinity stress on “Huangxuan No.1”Portunus trituberculatus to identify the characteristics and regulation of serum osmolarity and ion concentration of the crabs during their adaption to salinity change. Four salinity groups （salinity 5, 10, 20, and 50） and a control group （salinity 30） were tested in the experiment. Sampling of the four experimental groups was conducted at 3 h, 6 h, 9 h, 12 h, 24 h, 48 h, and 72 h. Sampling of the control group was at 0 h, 3 h, 6 h, 9 h, 12 h, 24 h, 48 h, and 72 h. We found that during 0-12 hours, the low salinity groups showed a decrease in the serum osmolarity whereas the serum osmolarity of the high salinity group was increased, compared to the control group. During 12–72 h, the serum osmolarity of all the experimental groups reached a steady state. Along with the increase in the salinity, the D-value between serum osmolarity and medium osmolarity was first reduced and then leveled off. The change in the concentrations of serum Cl^–, Na^＋, and K^＋ showed a same pattern as the change in the serum osmolarity. The D-value of the concentrations of Cl^– and Na^＋ between serum and medium also dropped first before reaching a plateau. The D-value of K^＋ concentration rose at first followed by a decline and eventually leveled off. These results indicated that “Huangxuan No.1” P. trituberculatus could be a hypertonic regulation crab. Cl^– and Na^＋ ions may play a key role in the osmolarity regulation.