鱼菜共生系统浮床覆盖率对金鲫摄食率的影响

Effects of floating bed coverage rate in aquaponics system on feeding rate of Carassius auratus red Variety

为研究金鲫-水蕹菜鱼菜共生系统对金鲫摄食率的影响,分别设置水蕹菜浮床覆盖率为0(A组,对照组)、30%(B组)和50%(C组)3组养殖系统,每组3个重复,每5 d作为1个摄食率周期,计算金鲫摄食率。在试验第25天取水样,检测水体总氨氮(TAN)、亚硝酸盐氮(NO2--N)和硝酸盐氮(NO3--N)等水质指标。结果显示,第1期、第2期,A、B、C各组摄食率差异不显著(P>0.05);第3期,摄食率开始呈现C组>B组>A组的趋势(P>0.05);第4期,C组摄食率显著大于A、B两组(P<0.05),B组大于A组,但差异不显著(P>0.05);第5期,各组间摄食率均存在显著差异,C组>B组>A组(P<0.05)。其中第5期,TAN浓度C组>B组>A组(P<0.05);NO2--N浓度和NO3--N浓度均为C组>B组>A组(P>0.05)。鱼体质量增长率及特定生长率B、C两组显著高于A组(P<0.05),C组菜长增长率显著高于B组(P<0.05)。试验结果表明,各系统稳定后,鱼菜共生系统更有利于提高金鲫摄食率,并且50%浮床覆盖率系统更有利于提高金鲫摄食率。

In order to study effects of aquaponics system of Carassius auratus red Variety-Ipomoea aquatica Forssk on feeding rate of Carassius auratus red Variety,Ipomoea aquatica Forssk floating bed coverage was 0(group A,control group),30%(group B)and 50%(group C),and 3 replicates were set up in each group.Feeding rate was calculated every 5 days as a feeding rate cycle.On the 25th day,water samples were taken to detect water quality indexes including total ammonia nitrogen(TAN),nitrite nitrogen(NO2--N)and nitrate nitrogen(NO3--N).Results showed that there was no significant difference in feeding rate among groups A,B and C in the first and second phases of experiment(P>0.05).In the third phase,feeding rate of groups B and C was higher than that of group A,among which,group C>group B>group A(P>0.05).In the fourth phase,feeding rate of group C was significantly higher than that of groups A and B(P<0.05),and that of group B was higher than that of group A,but difference was not significant(P>0.05).In the fifth phase,there were significant differences in feeding rate among all groups,group C>Group B>group A(P<0.05).TAN concentration was group C>group B>group A(P<0.05).Concentrations of NO2--N and NO3--N were group C>Group B>group A(P>0.05).Weight gain rate of Carassius auratus red Variety and specific growth rate of fish in groups B and C were significantly higher than those in group A(P<0.05),and growth rate of length of Ipomoea aquatica Forssk in group C was significantly higher than that in group B(P<0.05).In conclusion,aquaponic system was more beneficial to increase feeding rate of Carassius auratus red Variety,and the 50%floating bed coverage system was more beneficial to increase feeding rate of Carassius auratus red Variety.