| The activity of muscle Na+/K+-ATPase was first time combined with that of the gill Na+/K+-ATPase to evaluate the salinity adaptability of the subadult Macrobrachium nipponense acclimated for 1d, 2d, 4d and 8d in different combinations of temperature (15℃, 20℃, 25℃ and 30℃) and salinity (0‰, 7‰, 14‰ and 21‰). Oxygen Consumption Rate and Tissue Water Content were also used for this evaluation. We found that;(l)The temperature can affect the activity of Na+/K+-ATPase significantly, which result in the content differences of Na+/K+-ATPase at different temperature.(2) The activity of gill Na+/K+-ATPase decreased time coursely during the 8-day acclimation; after acclimation for 8 days, the activity of gill NaVKT-ATPase decreased with the increase of salinity, high temperature cart enhance this effect.(3) The activity of muscle Na+/K+-ATPase increased time coursely during the 8-day acclimation, but had not completely recovered within 8 days. This indicated that subadult Macrobrachium nipponense need a long time to adapt salinity changes.(4) Only at lower temperature could Oxygen Consumption Rate reflect the relationship between osmotic difference and energy requirement. This relationship can be concealed at optimum temperature when growth induced oxygen consumption represent most part of the oxygen consumption.(5) The content of tissue water can reflect status of growth. The tissue water got its greatest content in the animal bodies at 25℃. Tissue water decreased as a function of salinity.(6)The isosmotic point for subadult Macrobrachium nipponense is about 14‰, the optimum temperature for its growth is around 25℃. 21‰ salinity is harmful to subadult Macrobrachium nippoitense and, high temperature can enhance this harmful effect.(7) The activity of muscle Na+/K+-ATPase was a good parameter for evaluating osmoregulation, because it can reflect the adaptability of different salinity by revealing the transport function and thus the metabolism function.
|
PDF Full Text Request