Studies On The Technology Of Artificial Breeding And Culturing Of Nibea Albiflora

Main aquestions in Nibea albiflora aquaculture including the artificial breeding and the cultivation technique were systematically studied in this thesis.The main results were summarized as followed:1.Large-Scale artificial breeding test of Nibea albifloraIn order to understand the suitable conditions of artificial breeding of Nibea albiflora in ningde and improve the effectiveness of large-scale artificial seedling,we studied effect of water temperature,salinity and pH on the fertilized egg hatching,and effect of different culture water body on the artificial breeding technique of Nibea albiflora.It carried on indoor cement pool scale experiment on artificial breeding,single batch of big specifications fry(average length of 50.0 mm)emergence reached 2.347 million at the end of the good results.Below are experimental results:1)Effect of water temperature,salinity and pH on the fertilized egg hatchingThe hatching processes of the fertilization egg of Nibea albiflora were observed under important gradient conditions,including water temperature(16~31?,Each group of interval 3?,single factor experiment,the same below),salinity(17.16,21.08,24.99,28.91 and 32.82)and pH(6.0,7.0,8.0 and 9.0).The result showed that the optimized conditions to hatch fertilized egg of Nibea albiflora was salinity of 21.08~28.91,water temperature of 19~25 ? and pH of 7~8.Too high or low salinity,water temperature and pH from the optimized parameters significantly decreased the hatching rate of the fertilized egg of Nibea albiflora and rapidly increased the deformity rate of the newly hatched larvae.2)Effect of different culture water body on the artificial breeding technique of Nibea albifloraThree sorts of culture water bodies of 10 m~3,30 m~3 and 60 m~3 were designed in the experiment.The fertilized eggs of Nibea albiflora were placed into the nursery pond according to the size of the culture water body(~60 g/ m~3).During the entire experiment,we estimated the hatching rate of the fertilized egg of Nibea albiflora,the survival rate,growth(weight,body length and length)and other economic traits.The results were as followed:The hatching rate of the fertilization eggs of Nibea albiflora was relatively higher in greater culture water body,but hatching rate did not show significant different among groups.However,we found that the survival rates and growth of Nibea albiflora juveniles were statistically different among groups.The survival rate and growth of Nibea albiflora juveniles in 60 m~3 culture water body were significantly higher than those of smaller water bodies.This result demonstrated that the larger culture water body was important for the large-scale breeding of Nibea albiflora.3)Artificial breeding test of Nibea albifloraIn April 2013,Total 300 Nibea albiflora of 2 years old were choose from the fishing raft of the Sandu town of Ningde as the experimental parent fishes,and getting 15.99 kg zygote by artificial fertilization.After 22 hour 25 min,larvae were hatched from the fertilized eggs under the condition of 24.5~26.8 ? water temperature,24.5~26.3‰ salinity,5.5~7.5 mg/L dissolved oxygen and 8.0 of pH.After 50 d cultivation,about 3.8 million juvenile fish were cultivated with an average total length of 5.0 cm,and the survival rate was about 14.4%.It was the first time to report that the number of Nibea albiflora got over one million.For the Nibea albiflora aquaculture farmer in Ningde City Jiaocheng,these fishes met their demand and promoted the development of aquaculture.4)Test of stress resistance of Nibea albiflora's juvenile fishTo understand the ability of resisting main environmental factors of Nibea albiflora juvenile,performing an assay of resisting temperature,salinity,pH and drying so that providing reference for transportation,clturation in the sea and quality evaluation of Nibea albiflora.The experiment was designed to analyze the stress resistance of Nibea albiflora juveniles on water temperature(12,14,16,18,30,32,34 and 35 ?),salinity(2,4,34,36,38 and 40),pH(4.2,4.4,4.6,4.8,9.2,9.4,9.6 and9.8)and air-exposure.The results illmuniated that water temperature tolerance range of Nibea albiflora juvenile was 16~32 ?,salinity tolerance range was 5~35 and pH tolerance range was 5.0~9.4.Meanwhile,Nibea albiflora juveniles began to die after 3.5 min exposed to air,indicating that Nibea albiflora juveniles were rather susceptible to hypoxia.2.Culturing technology of Nibea albiflora.Researching the effects of cage size on Nibea growth and designing assay of large-scale sea cage culture and indoor factory breeding(flow-through).The results were as followed:(1)At the same culture density,the growth of Nibea albiflora in 8m×8m×5m net cage was significantly higher than that in 4m×8m×4m net cage,and the difference was more significant in the later period of culture.After 5 months net cage culture,the growth of Nibea albiflora in 8m×8m×5m net cages was significantly faster than that in 4m×8m×4m net cages from October.After 5 months culture,the survival rate of Nibea albiflora in4m×8m×4m and 8m×8m×5m net cages were about 85.0% and 86.4%,respectively.(2)Nibea albiflora of 5.0 cm of the average total length was cultured in 10 4m×8m×4m net cages according to the improving management methods.After net cage culture for 16 months,the survival rate of Nibea albiflora reached 59.29%,the average body weight was 437.28 g;but the survival rate of Nibea albiflora which was obtain by common fishermen's culturation was about 45%,the average body weight was 300~350g.(3)After in-door and industrialized culture for 6 months,the average body weight of Nibea albiflora reached 163.45 g,and average body length was 20.0 cm.The survival rate in running water ponds was as high up to 88.7%.