中华鲟幼鱼渗透调节器官组织结构在海水条件下的适应性调整

Adaptive adjustment of osmotic organ structure of juvenile Chinese sturgeon in seawater conditions

中文关键词: 中华鲟  渗透调节  组织结构  海水条件

英文关键词: Chinese sturgeon  Osmoregulation  Organization structure  Seawater conditions

中文摘要:

      本研究以淡水养殖中华鲟(Acipenser sinensis)幼鱼为研究对象，采用连续升盐的方式实施海水驯化实验，对驯化过程中不同盐度下中华鲟幼鱼渗透调节器官鳃、肾和肠组织结构进行比较研究，以期了解各器官在渗透调节过程中的适应性变化。结果显示，中华鲟幼鱼在海水条件下存活率达100%；海水驯化过程中，随着盐度的升高，中华鲟幼鱼鳃小片宽度显著减小(P<0.05)，相邻鳃小片间距、泌氯细胞直径显著增加(P<0.05)，表明中华鲟幼鱼从淡水环境逐渐向海水环境适应过程中，通过改变鳃小片宽度及相邻间距，加快机体与外界水氧交换量，增加泌氯细胞大小，提高细胞代谢水平，以应对海水环境的高渗透压。同时，中华鲟幼鱼肾小球长径在海水驯化过程中显著减小(P<0.05)，同时数量也略有减少，表明中华鲟幼鱼通过降低肾脏的滤过功能减少机体水分丧失，以适应外界环境渗透压的变化。肠道组织结构未观察到明显变化。研究表明，中华鲟幼鱼具有较强的海水适应能力，渗透调节器官主要通过改变鳃小片宽度和间距、泌氯细胞大小及肾小球大小和数量来适应海水盐度变化。

英文摘要:

      The “land-sea-land” breeding pattern has become an important strategy for the rearing of Chinese sturgeon. In this study, juvenile Chinese sturgeon (Acipenser sinensis) in freshwater culture were utilized as the research object and an acclimation experiment was performed using continuous saltwater rearing conditions. To understand the adaptability changes of organs during osmoregulation, a comparative study was conducted on the structure of the gills, kidneys, and intestinal tissues of juvenile Chinese sturgeon grown in different salinities during seawater acclimation. The results showed that the survival rate of juvenile Chinese sturgeon in the seawater was 100%. During seawater acclimation, the breadth of the gill lamella significantly decreased (P<0.05), whereas the spacing of the gill lamella and chloride cell diameter significantly increased (P<0.05), suggesting that these juvenile Chinese sturgeon from a freshwater environment gradually adapted to a seawater environment by changing their gill lamella breadth and the space between the adjacent gill lamella, sped up their body and oxygen exchange capacity with the outside water conditions, and increased the chloride secretory cell sizes to improve the level of cell metabolism to cope in a water environment with high osmotic pressure. The glomerular diameter of the juvenile Chinese sturgeon decreased during seawater acclimation (P<0.05), and the number of glomerular decreased slightly; therefore, the juvenile Chinese sturgeon decreased the loss of body water by reducing the filtration function of their kidneys to adapt to the changes in osmotic pressure of the external environment. However, no obvious changes were observed in the intestinal tissue structure. The results showed that the juvenile Chinese sturgeon had strong seawater adaptability and osmotic adjustment of organs that adapted to the changes in seawater salinity by changing the breadth and spacing of their gill lamella, the size of the chlorine secretory cells, and the size and number of the glomerular.