| 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. |
