水温和盐度对南美白对虾幼虾能量收支的影响

用室内生态实验法测定了南美白对虾幼虾在不同盐度(5,15或25)和水温(20～23℃,25℃,30℃或33℃)下摄食水丝蚓的能量收支方程。在盐度5～25时,随盐度降低,对虾的能量转换效率升高,同化率降低。在盐度为5时,K1最高(29.02%),同化率最低(77.89%)。对虾具补偿机制来补偿调节渗透压的能耗。盐度对同化率的影响,主要是通过影响呼吸代谢实现的。对虾的特定生长率(y)(%·d-1)随水温(X)(℃)上升而增加,其关系式为:y=0.0168LnX 0.0831(R2=0.9324)。对虾在较高温度下生长快,主要是增加绝对摄食量,提高吸收效率,减少粪便排泄量。在相同温度下,变温时对虾的摄食量高于恒温时。

Effects of water temperature and salinity on energy budget of Penaeus vannamei juveniles

Components of energy budgets of Pacific white shrimp( Penaeus vannamei ) juveniles with body length of 4. 5- 5. 0 cm fed on Limnodrilus sp. were measured at different water temperatures ( 20- 23 .. , 25 .. , 30 .. or 33 .. ) ) and salinities( 5, 15 or 25) by an experimental ecological method to improve husbandry for shrimp culture. The result s indicated that there were decrease in assimilation efficiency and increase in energy conversion efficiency with salinity increment within the range of 5- 25. At 5, there were the highest K1( 29. 02%) and the lowest assimilation eff iciency ( 77. 89% ) by the juveniles. The ef fect of salinity on assimilation eff iciency was dependent on respiration energy and compensative mechanism. There was an increase in specific growth rate ( y ) of the shrimp with water temperature ( X , .. ) increment as the fo llowing equation: y= 0. 0168lnX 0. 0831 ( R 2 = 0. 9324) . Better growth at high temperature is attributed to the high food consumption, high absorption and less feces. At the same water temperature, the shrimp has higher food consumption at fluctuated water temperature than at constant water temperature.