投饵量对许氏平鲉幼鱼生长和水环境中污染指标的影响

摘要

The effects of feeding amount (30, 38, 46, 54, 62, 70, 86, 102, 120, 140, 160, 180, 200, or 240 mg/d) on weight gain and water quality including suspended material level, chemical oxygen demand ( COD) and ammonia nitrogen ( NH4+ -N) was studied in aquaculture of Schlegel's rockfish Sebastes schlegeli. Results showed that the growth of the fish was shown to increase with increase in feeding amount ranging from 30 mg/d to 160 mg/d. However, the fish had no weight increment when the fish was fed at a feeding amount of greater than 160 mg/d. The relationship of feeding amount with apparent suspended substance apparent COD levels and apparent ammonia nitrogen levels was found to be highly consistent with the relationship of feeding amount with weight gain. There existed an excessive feeding indication point, 5Z, a COD pollution indication point, Cz, and an ammonia nitrogen pollution indicating point NZ. When the feeding amount was below Sz, Cz and Nz, the apparent suspended material level, apparent COD level and apparent ammonia nitrogen level were increased slowly with the increase in feeding amount; when the feeding amount was found above Sz, Cz and Nz, however, apparent suspended material level, apparent COD level and apparent ammonia nitrogen level were increased rapidly. Self-purification in aqua-culture water was the same as general water. The feeding amount( T) - apparent suspended material level(S) model was established; S = -18. 86 + 1. 082T-0. 0069T2+0. 0002T3; feeding-apparent COD level excretion model: COD=0. 16+0. 977T-0. 055T2+0. 00017T3; and COD-self-purification model:C=113.4exp(-0.68t).%研究了许氏平鲉Sebastes schlegeli幼鱼养殖过程中投饵量(30、38、46、54、62、70、86、102、120、140、160、180、200、220、240 mg/d)对鱼体的增重及对水环境中悬浮物、化学需氧量(COD)、氨氮(NH4+-N)含量的影响.结果表明:幼鱼在生长过程中的最佳投饵量为160 mg/d,当投饵量小于160mg/d时,许氏平鲉的增长速度随投饵量的增加而增加；当投饵量大于160 mg/d时,再增加投饵量也并不能提高幼鱼的增长速度.投饵量对水体中固体悬浮物、COD、氨氮含量的影响与投饵量对幼鱼增重的影响的结果具有高度的一致性,存在投饵过量指示点(Sz)、COD污染指示点(Cz)、氨氮污染指示点(Nz).当投饵量小于Sz、Cz、Nz时,悬浮物、GOD、氨氮含量均随投饵量的增加而缓慢增加；当投饵量大于Sz、Cz、Nz时,悬浮物、COD、氨氮含量迅速增加.养殖水体中COD的自净符合一般水体COD的自净规律.根据试验结果建立了投饵量(T)与悬浮物含量(S)的模型为S=-18.86+1.082T-0.0069T2+0.0002T3,投饵量与COD的模型为COD=0.16十0.977T-0.055T2+0.00017T3,COD自净模型为C=113.4×exp(-0.68t).