采用饲养试验方法,研究了平均体质量为(7.16±0.07)g的大菱鲆(SCOPHTHAlMuS MAXIMuS)幼鱼分别在盐度12、18、24、30和36下饲养60 d后,其鳃nA+-k+-ATPASE活力、血清离子浓度、生长激素(gH)、皮质醇激素(COr)、特定生长率(Sgr)和饲料效率(fCE)的变化。结果表明:幼鱼鳃nA+-k+-ATPASE活力、血清nA+浓度均随盐度的升高而上升,分别在3.48~8.30 u/Mg和169.99~180.00 MMOl/l之间,其中12盐度组最低,36盐度组最高。幼鱼血清中k+和Cl-浓度分别在2.20~3.47 MMOl/l和136.67~142.00 MMOl/l之间,各盐度组之间差异不显著。幼鱼血清中gH和COr浓度分别在0.41~1.66 ng/Ml和35.33~76.41 ng/Ml之间;其中gH在36盐度组最高,12盐度组最低,而COr在12盐度组最高,36盐度组最低。幼鱼Sgr和fCE分别在(1.45~2.00)%/d和1.12%~1.38%之间,与盐度的相关性不显著,两者均为12盐度组最低。由此可见,盐度变化显著影响大菱鲆幼鱼鳃nA+-k+-ATPASE活力、血清nA+浓度和激素含量。本研究对大菱鲆养殖生理生态条件分析具有重要参考意义,研究结果可为大菱鲆养殖的盐度选择提供理论依据。The Na+-K+-ATPase activity in gill,concentrations of ions and hormones in serum,and specific growth rate and feed conversion efficiency of juvenile turbots( Scophthalmus maximus)( body weight of 7.16 ±0.07 g),which have been reared at salinities 12,18,24,30 and 36 for 60 days,were investigated.The results showed that Na+-K+-ATPase activity and Na+concentration were 3.48- 8.30 U /mg and 169.99-180.00 mmol /L,respectively,and their levels increased with the rise of water salinity.The highest values were observed at salinity 36,and lowest ones at salinity 12.The Na+-K+-ATPase activity and Na+concentration inthe fish reared at salinity 12 were significantly lower than those in the control( P 0.05).Growth hormone and cortisol levels were 0.41- 1.66 and35.33- 76.41 ng /ml,respectively.Growth hormone level was the lowest in the fish reared at salinity 12,and the highest at salinity 36,both of which had significant difference compared to that of the control( P 0.05).Specific growth rate and feed conversion efficiency were( 1.45-2.00) % /day and 1.12%- 1.38%,respectively.Although both were the lowest at salinity 12,they were not significantly correlative with salinity.Thus,the results indicate that the changes in salinity could have significant impacts on Na+-K+-ATPase activity in gill,concentrations of Na+,growth hormone and cortisol in serum of juvenile turbots.The results provide important reference for salinity selection in turbot mariculture.现代农业产业技术体系专项资金(No.CARS-50
