Study On Pseudobagrus Fulvidraco Cultured In Biofloc Aquaculture System

The traditional pond intensive culture model is a kind of aquaculture model which can achieve the aim of high density breeding through the large amount of water changing,the large amount of medicine to maintain the water quality of the cultured water body and the health of the cultured animals.But this farming model also caused the natural water pollution,frequent disease and aquatic product safety and many other issues.The traditional pond intensive farming model has seriously hampered the healthy development of aquaculture in China.Closed recirculating aquaculture system refers to the aquaculture of water through the physical and chemical methods to deal with,to achieve the recycling of aquaculture water.Biofloc technology breeding mode is through the aquaculture of water in the microbial assimilation and nitrification to achieve the treatment of nitrogen emissions to aquaculture water,to achieve zero change of water farming model.These two farming models are an important direction for the development of aquatic industry in China.The results of the breeding of Pelteobagrus fulvidraco in these two farming modes are rarely reported.The experiment is divided into the following three parts.1.Comparative Study on the Culture Effect of Pelteobagrus fulvidraco in Biofloc technology culture system and Recirculating aquaculture systemIn order to study the growth and immunity of Pelteobagrus fulvidraco in the field of Biofloc technology culture system and Recirculating aquaculture system,the recombinant fish culture was carried out by Recirculating aquaculture system(RAS)and Biofloc technology(BFT)(9.68±1.50)g for 60 d.The results showed that the total ammonia nitrogen and nitrite nitrogen were at a low concentration throughout the experiment,and the total ammonia concentration in the BFT group was higher than that in the RAS group from the 12 th day.At the end of the experiment,the terminal densities of the RAS group and the BFT group were(4.22 ± 0.57)and(3.45 ± 0.65)kg / m3,respectively.The mean mass,weight gain and specific growth rate of the RAS group were significantly higher than those of the BFT group.There were no significant differences in gastric lipase,intestinal lipase,pepsin,trypsin,alkaline phosphatase and total superoxide dismutase activity and plasma triglyceride and blood glucose levels between the RAS and BFT groups at the end of the experiment(p> 0.05).The plasma total protein and total cholesterol in the RAS group were significantly higher than those in the BFT group(p <0.05).2.Effects of different feed C / N on the Biofloc technology culture system of Pelteobagrus fulvidracoIn order to study the suitable feed C / N for the breeding of Pelteobagrus fulvidraco,the effects of different C / N ratios on water quality and growth,digestion and immunity of Pelteobagrus fulvidraco were analyzed experimentally.The control group was fed with basal diet(C / N 8.0: 1).The control group added glucose to the basal diet,and the control C / N was 12: 1 and 16: 1,respectively.The results showed that the total ammonia nitrogen and nitrite nitrogen concentrations were significantly lower in the three groups during the whole experiment period,and the total ammonia concentration in the C / N 8 group was significantly higher than that in the C / N12 and 16 groups(p> 0.05)at the end of the experiment.Three groups of nitrate nitrogen in the whole process of farming have continued to accumulate.At the end of the breeding,there was no significant difference between the final density,the final mass and the bait coefficient.At the end of the experiment,there were no significant differences in gastric lipase,pepsin and trypsin activity between the three groups(p> 0.05).There was no significant difference in the lipase activity between the C / N16 and 12 groups(p> 0.05)/ N8 group,C / N16 and 8 groups were significantly higher than those in C / N12 group(p <0.05).3.Effects of Different Total Solid Suspensions on the Culture of Pseudobagrus fulvidracoIn order to study the effects of different total solid suspended solids(MLSS)on the growth,water quality,digestion and nonspecific immunity of Pseudobagrus fulvidraco,the MLSS in Biofloc technology culture system was studied in this paper.(Group L),350-400 mg / L(group M)and 750-800 mg / L(group H),and cultured for 30 days.The results showed that different MLSS had no significant effect on the growth of Pelteobagrus fulvidraco.During the whole experiment,the total ammonia nitrogen and nitrite nitrogen in the three groups were at a low concentration,and the nitrate accumulation continued.At the end of the experiment,the gastric lipase activity of the three groups was H group> M group> L group(p <0.05).The activity of lipase in group M and group H was not significantly different(p> 0.05)(P <0.05).The activity of trypsin in group L and group H was not significantly different(p> 0.05)and lower than that in group M(P <0.05).