| In recent years, the rapid development of shrimp aquaculture industry in our country increased very quickly. At present, shrimp aquaculture industry in our country mainly cultured Litopenaeus vannamei. Traditional farming method is outdoor high density breeding patterns which would be potential harm to the shrimp aquaculture by weather change. In order to reduce the sudden change of the weather effect on water quality and Litopenaeus vannamei stress stimulation, to create a new farming method Greenhouse High-Intensive Ponds. Based on the research about breeding density, Water quality control measures we get follo Wing experimental results:1. Different breeding density effect on Greenhouse High-Intensive Ponds Water quality, growth characteristics and breeding benefit.Monitoring pool 1~4 of the breeding cycle in Zhejiang province Fenghua Xianghe ecological farming garden. No1,2 tank and No. 4,3 tank, seedling density Were 315ind/m2 and 375ind/m2. Through the 70 d culturing, discusses the effect of stocking density on shrimp growth Water quality and breeding effect. The results show that with the increase of the breeding density index the Water quality have no significant difference(P>0.05). The main Water quality indexes TAN(0.265~4.224mg/L) and NO2--N(0.001 ~ 4.290 mg/L)within the scope of its security growth; The growth and culture benefit of two densities have no significant difference(P>0.05); The body weight gain and body length growth of density 375ind/m2, 315ind/m2 were 1.19g/w, 1.12g/w 0.96cm/w, 0.94cm/w; Density of 375 ind/m2, 315ind/m2 the output of per unit water were 1.54kg/m2 and 1.32kg/m2(the average application of each density value).By tracking NO.1~4 pools of litopenaeus vannamei body length and body weight to study the growth characteristics. The results showed that:(1)Two kinds of density body length and weight density was power function W=a Lb, 1~4 pool equation respectively:(pond 1)W = 0.023L2.690(R2 = 0.998)、(pond 2)W = 0.025L2.767(R2 = 0.999)、(pond 3)W = 0.027L2.745(R2 = 0.995)、(pond 4)W = 0.024L2.740(R2 = 0.999);Body weight and length growth is allometric growth, before 40d(L<4.4~5.18cm)body weight gain rate is far lower than the body length, after 40 d body weight grow at a faster rate;(2) the relationship between body weight and culture time were significant exponential relationship, 1~4pool equation respectively:(pond 1)W= 0.063e0.078d(R2= 0.847), W= 0.063e0.078d(pond 2)(R 2= 0.847),(3 pools)W=0.072e0.079d(R2 = 0.837),(4 pools)W= 0.044e0.074d(R 2 = 0.868); The the average body weight gain rate of 1、2pool and 3、4pool have no significant difference(P>0.05) in the breeding cycle;(3) the body length and breeding time appears to be a linear relationship that is uniform growth, 4 pools equation respectively(pond 1)L= 0.113 d +0.978(R2 = 0.986), L=0.110 d +1.023(pond 2)(R2=0.983), L= 0.114d(pond 3) +0.758(R2 = 0.982),(4 pool) L= 0.117 d +0.788(R2 = 0.984);(4) the stocking density of 315ind/m2 and 375ind/m2 had no significant difference in growth characteristics, stocking density 315~375ind/m2 is worthy to be popularized in Litopenaeus vannamei farming.2. The effect of different control measures for water qualityExperiment using simple measures such as changing the water, food control, oxygen increasing machine and microbial preparation regulate pond water quality were obtained certain result that the main water quality indexes get different degrees of improvement. When the change of content of 20%, decreased TAN、NO2-N、NO3-N and CODMn in varying degrees, of which TAN and CODMn were significantly lower(34.7% versus 29.9%, P<0.05); Opening aerator only improved significantly on DO and TAN, DO increased significantly(11.8% vs 29.4%, P<0.05), TAN decreased significantly(34.8% and 34%, P<0.05); Excessive feeding, can significantly increase the content of TAN(daily feeding amount of 39kg/d, TAN increase 17.9%); Using microbial agents only NO3-N decreased by 20.1%(P<0.05), the other indexes did not appear significant reduction(P>0.05). Therefore, in Greenhouse High-Intensive Ponds culturing Litopenaeus vannamei should be aimed at the pond water quality situation to take reasonable simple measures control water quality. |
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