盐度和温度对条石鲷幼鱼能量收支的影响

Effects of salinity and temperature on energy budget of juvenile Oplegnathus fasciatus

以条石鲷幼鱼(初始体重5.46 g)为试验对象,研究不同盐度(17.5‰,22.5‰,27.5‰,32.5‰,37.5‰和42.5‰)和不同温度(18℃,22℃,26℃和30℃)对条石鲷幼鱼生长及能量收支的影响。结果表明:盐度和温度对条石鲷幼鱼的特定生长率、摄食率、转化效率及能量收支分配率均有显著影响,但对吸收效率影响不显著。在盐度为22.5‰,温度为22℃时,条石鲷幼鱼的特定生长率、转化率、摄食率、吸收率及生长能分配率均达到极大值,而排粪能、排泄能及代谢能分配率则处于较低水平。即在盐度22.5‰,温度22℃时,条石鲷幼鱼分别得到最佳的能量分配模式,此时的饵料系数最低,生长最快,是条石鲷幼鱼的最优养殖条件。能量收支方程分别为:100.00C=7.97F+8.66U+26.47G+56.90R(盐度22.5‰);100.00C=11.52F+6.13U+18.96G+63.39R(温度22℃)。研究发现,条石鲷幼鱼属于高代谢、低生长型鱼类。

Using juvenile Oplegnathus fasciatus （ initial body weight 5.46 g） as experiment objects, we have studied the effects of different levels of salinities （ 17. 5‰, 22.5‰, 27.5‰, 32.5‰, 37.5‰ and 42. 5‰） and temperatures （ 18℃ , 22℃C , 26℃ and 30℃） on the growth and energy budget. The results showed that the specific growth rate （SGR） , consumption rate （CR） , conversion efficiency （CE） and energy budget of juvenile Oplegnathus fascia- tus were affected significantly by salinity and temperature, but the energy absorption efficiency （AE） was not affected. The SCR, CR, CE, AE and growth energy of juvenile Oplegnathusfasciatus reached a maximum level when the salinity was 22. 5‰ and temperature 22℃. However, the distribution rate of feces energy, excretion energy and metabolizable energy were all at a lower level under this condition. These results implied that the energy distribution pat- tern of juvenile Oplegnathus fasciatus was the best under these conditions and it was the best culture environment of juvenile Oplegnathus fasciatus. The optimal energy equation at this level was： 100. 00C = 7. 97F ＋ 8. 66U ＋ 26. 47G ＋ 56. 90R（salinity 22. 5‰） ;100. OOC = 11.52F ＋ 6. 13 U ＋ 18.96G ＋ 63.39R （ temperature 22℃ ）. The resuhs demonstrated that juvenile Oplegnathus fasciatus is a type of fish with high metabolism activity but low-growth rate.