Effects of Na^+/K^+ Ratio of Groundwaters on the Gill Ion-Transport Enzyme Activity,Plasma Osmolality and Growth of Cynoglossus semilaevis Juveniles  

作　　者：YANG Huizan PAN Luqing HU Fawen LIU Hongyu 

机构地区：[1]The Key Laboratory, of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, P. R. China

出　　处：《Journal of Ocean University of China》2008年第4期447-452,共6页中国海洋大学学报（英文版）

基　　金：the Agricultural Science and Technology Achievement Transfer Project of Tianjin City of China (Transfer of the Large-scale health culture technology of fish and shrimp);the Science and Technology Program of Shengli Oil Field Administration Bureau (The exploring study on the culture technology of fish and shrimp using saline groundwaters)

摘　　要：The effects of environmental Na+/K+ ratio on the gill ion-transport enzyme activity,plasma osmolality and growth of Cynoglossus semilaevis juveniles were investigated. The results showed that,plasma osmolality was similar among flounder adapted to different Na+/K+ ratios of saline groundwaters (P>0.05),while the growth,gill Na+,K+-ATPase and HCO3--ATPase activities were affected by Na+/K+ ratio significantly (P<0.05). The gill Na+,K+-ATPase activity reached its maximum on day 3,then decreased gradually from day 3 to day 9 and remained constant from day 9 to day 15. The peak values of gill Na+,K+-ATPase activity were detected on day 3 for all Na+/K+ ratios of saline groundwaters,then the enzyme activities descended,and on day 9 the enzyme activi-ties achieved steady state,and the gill HCO3--ATPase activity increased rapidly and achieved steady state after one day. During steady state,the gill Na+,K+-ATPase and HCO3--ATPase activity of Na+/K+ ratios 20 and 40 treatments were significantly higher than those in the control group (Na+/K+ ratio 27.5),while there were no significant differences between the Na+/K+ ratio 30 treatment and the control group; the gill Na+,K+-ATPase activity of Na+/K+ ratio 20 and 40 treatments were significantly higher than that for ratio 30 treatment,but there were no significant differences of gill HCO3--ATPase activity among these treatments. At the end of the 15-day experiment,the weight gain (%) and specific growth rate (SGR) of flounders maintained in seawater were significantly higher than those in groundwaters; significant differences also occurred among the treatments; Na+/K+ ratio 30 treatment had the highest values (33.7% and 1.94 respectively),which were significantly higher than those under Na+/K+ ratios 20 and 40 treatments. There-fore,for the saline groundwater used in this experiment,it is suggested that the Na+/K+ ratio be adjusted to approximately 30,i.e.,as close to that of natural seawater as possible in the culture of flounder.The effects of environmental Na^-/K^-ratio on the gill ion-transport enzyme activity, plasma osmolality and growth of Cynoglossus semilaevis juveniles were investigated. The results showed that, plasma osmolality was similar among flounder adapted to different Na^-/K^＋ ratios of saline groundwaters （P〉0.05）, while the growth, gill Na^-, K^＋-ATPase and HCO3^--ATPase activities were affected by Na^-/K^-ratio significantly （P〈0.05）. The gill Na^＋, K^--ATPase activity reached its maximum on day 3, then decreased gradually from day 3 to day 9 and remained constant from day 9 to day 15. The peak values of gill Na＆＋, K^＋-ATPase activity were detected on day 3 for all Na^-/K^- ratios of saline groundwaters, then the enzyme activities descended, and on day 9 the enzyme activities achieved steady state, and the gill HCO3^＋-ATPase activity increased rapidly and achieved steady state after one day. During steady state, the gill Na^＋, K^＋-ATPase and HCO3^＋-ATPase activity of Na^＋/K^＋ ratios 20 and 40 treatments were significantly higher than those in the control group （Na^＋/K^＋ ratio 27.5）, while there were no significant differences between the Na^＋/K^＋ ratio 30 treatment and the control group; the gill Na^-, K^＋-ATPase activity of Na^＋/K^- ratio 20 and 40 treatments were significantly higher than that for ratio 30 treatment, but there were no significant differences of gill HCO3^--ATPase activity among these treatments. At the end of the 15-day experiment, the weight gain （%） and specific growth rate （SGR） of flounders maintained in seawater were significantly higher than those in groundwaters; significant differences also occurred among the treatments; Na^＋/K^- ratio 30 treatment had the highest values （33.7% and 1.94 respectively）, which were significantly higher than those under Na^＋/K^＋ ratios 20 and 40 treatments. There- fore, for the saline groundwater used in this experiment, it is suggested that the Na^-/K^- ratio be adjusted to approximately 30,

关 键 词：Na^-/K^- ratio Cynoglossus semilaevi ion-transport enzyme activity plasma osmolality growth 

分 类 号：P641.2[天文地球—地质矿产勘探]