Studies On The Optimum Water Temperature And Stocking Density And The Main Pathogenic Bacteria In Culturing Anguilla Marmorata

Anguilla marmorata is a new introduction species of eels aquaculture recently in China,and the research on the the cultivation techniques of it and the disease of breeding process of it are rarely lack.The suitable temperature and density on the growth of Anguilla marmorata in circulating water system were studied and the pathogenic bacteria of Anguilla marmorata in the culture process were identified in the paper and the epidemic regularity of pathogenic bacteria were general summary.The main results are shown as follows:The water temperature had a significant effect on the daily weight gain(DWG),feeding rate(FR)and specific growth rate(SGR)of Anguilla marmorata.Anguilla marmorata with size of 117.23 ± 4.64 g/ind was identified in this experiments and three water temperature levels of 26 ?,29 ?,and32 ? were designed to culture for 30 days and the results indicated that according to quadratic regressions between DWG,FR,SGR and temperature,the maximum DWG occurred at 29.17 ? and the maximum FR occurred at 29.82 ? and the maximum SGR occurred at 29.26 ?,so the suitable growth temperature range of Anguilla marmorata is 29 ?-30 ?.Anguilla marmorata with size of 197.62 ± 7.98 g/ind was identified in this experiments and three water temperature levels of 28 ?,30 ? and 32 ? were designed to culture for 30 days and the results indicated that according to quadratic regressions between DWG,FR,SGR and temperature,the maximum DWG occurred at 29.07 ? and the maximum FR occurred at 29.09 ? and the maximum SGR occurred at 28.95 ?,so the suitable growth temperature range of Anguilla marmorata is 28.5 ?-29.5 ?.Anguilla marmorata with size of 260.83 ± 17.01 g/ind was identified in this experiments and three water temperature levels of 26 ?,29 ?,and32 ? were designed to culture for 30 days and the results indicated that according to quadratic regressions between DWG,FR,SGR and temperature,the maximum DWG occurred at 29.36 ? and the maximum FR occurred at 30.32 ? and the maximum SGR occurred at 29.43 ?,so the suitable growth temperature range of Anguilla marmorata is 29 ?-30.5 ?.Anguilla marmorata with size of 451.49 ± 12.78 g/ind was identified in this experiments and three water temperature levels of 28 ?,30 ? and 32 ? were designed to culture for 30 days and the results indicated that according to quadratic regressions between DWG,FR,SGR and temperature,the maximum DWG occurred at 29.12 ? and the maximum FR occurred at 28.79 ? and the maximum SGR occurred at 29.02 ?,so the suitable growth temperature range of Anguilla marmorata is 28.5 ?-29.5 ?.The stocking density had a significant effect on the daily weight gain(DWG),feeding rate(FR),specific growth rate(SGR)and food conversion ratio(FCR)of Anguilla marmorata.Anguilla marmorata with size of 139.76 ± 5.49 g/ind was identified in this experiments and three density levels of 35.29 kg/m3,41.18 kg/m3,and 47.06 kg/m3 were designed to culture for 90 days at 30 ?-33.5 ?,and the density were 50.59 kg/m3,55.29 kg/m3,and 60.24 kg/m3 at the end of the experiments.The results indicated that the maximum DWG,the maximum FR,the maximum SGR and the minimum FCR occurred in 35.29 kg/m3,so under the condition of the density in the experiments,the suitable stocking density of Anguilla marmorata is 35.29 kg/m3.Anguilla marmorata with size of 334.35 ± 40.18 g/ind was identified in this experiment and three density levels of 35.29 kg/m3,47.06 kg/m3,and 58.82 kg/m3 were designed to culture for 90 days at 30 ?-33.5 ?,and the density were 48.76 kg/m3,62.82 kg/m3 and 73.65 kg/m3 at the end of the experiments.The results indicated that the maximum DWG,the maximum FR,the maximum SGR and the minimum FCR occurred in 35.29 kg/m3,so under the condition of the density in the experiments,the suitable stocking density of Anguilla marmorata is 35.29 kg/m3.Anguilla marmorata with size of 528.85 ± 59.37 g/ind was identified in this experiments and three density levels of 35.29 kg/m3,47.06 kg/m3 and 58.82 kg/m3 were designed to culture for 90 days at 30 ?-33.5 ?,and the density were 45.71 kg/m3,63.41 kg/m3 and 71.24 kg/m3 at the end of the experiments.The results indicated that the maximum DWG,the maximum SGR and the minimum FCR occurred in 35.29 kg/m3 and,the maximum FR occurred in 47.06 kg/m3,so under the condition of the density in the experiments,the suitable stocking density of Anguilla marmorata is 35.29 kg/m3.The pathogenic bacteria of Anguilla marmorata in the culture process were identified in the paper.There were 51 Anguilla marmorata detected and the pathogenic bacteria strains were separated and purificated from the gill,intestine and liver of Anguilla marmorata,and the significantly different single colonies were selected to identify.After identification,31 strains of pathogenic bacteria were identified as Aeromonas hydrophila(9),the detection rate of it is 17.65%;Citrobacter freundii(7),the detection rate of it is 13.73%;Aeromonas bestiarum(4),the detection rate of it is 7.84%;Vibrio fluvialis(2),the detection rate of it is 3.92%.The studies showed that the water temperature and the stocking density had significant effects on the feeding and growth of Anguilla marmorata.The pathogenic bacteria of Anguilla marmorata in the culture process were identified as Aeromonas hydrophila,Citrobacter freundii,Aeromonas bestiarum,Vibrio fluvialis.The conclusions of this study provide guidance to the cultivation of Anguilla marmorata and have scientific reference on research and diagnosis of bacterial pathogens of Anguilla marmorata.