The Research On Comprehensive Technique Of Prevention And Control Of Disease In Pelodiscus Sinensis

Along with the fast development of Pelodiscus sinensis' aquaculture in Hebei province,the occurrence of pelodiscus sinensis' disease also increasingly stands out.In order to prevent and control the occurrence of Pelodiscus sinensis' di-sease,also to decrease the huge economic loss bringing to raising turtle,we carryed on an epidemiological survey of Pelodiscus sinensis to find out the patronymic condition,the prevalent regulation and the disease attribute ,which directed at 1256 mu culture area from six counties and cities in Hebei province from Apr. to Oct. in 2010;On that basis,we confirmed the aetiological agent of Pelodiscus sinensis in Hebei province and put forward the corresponding control measure. The major research included:By the means of the epidemiological survey of Pelodiscus sinensis in Hebei province from Apr. to Oct. in 2010,we finded that aetiological agent of Pelodiscus sinensis' disease was mainly biological pathogeny,whose percentage reached up to 92.3%.In biological diseases,bacterial disease took the first place,whose percentage was 66.67%,and the percentage of both viral disease and fungoid disease was 16.67%.Most of Pelodiscus sinensis' diseases was Red abdominal shell disease of soft-shelled turtle,and the following were White abdominal shell disease of soft-shelled turtle,Soya sheet disease,White dot diseases and so on;Aug. Was a month when the rate of pathogenic bacteria's diseases was the highest,and the highest morbidity was 6.42%,the death rate was to 3.24%.We isolated and purified four pathogenic bacterias from ill Pelodiscus sinensis,which were identified respectively as Aeromonas hydrophila,Aeromonas veronii,Dull Edwardsiella tarda and Citrobacter freundii.We composed four pairs Auele Specific Primers based on the gene sequence of 16S in the four pathogenic bacterias and we also established multiple PCR detection method for the four pathogenic bacterias.Specific tests indicated that that method could augment the positive band of those four pathogenic bacterias.We used template-dilution method to test the sensibility of multiple PCR detection method.The lowest detection level of multiple PCR detection method was one Dull Edwardsiella tarda ,one Aeromonas hydrophila,three Citrobacter freundii and nine Aeromonas veronii.We employed check experiment to detect the treatment effect of Chinese medicinal herb and Western medicine to Pelodiscus sinensis' diseases,also to measure the effect of Chinese medicinal herb on Pelodiscus sinensis' immunity and the condition of drug residue.Experiments indicated that the protective rate of Chinese medicinal herb and Western medicine to Pelodiscus sinensis was respectively 77.1% and 79.1%,which rarely differed.The measurement of hemocyte's phagocytosis, seroscopy's valence and serum's sterilization vigour made it clear that Chinese medicinal herb could markedly enhance Pelodiscus sinensis' immunity;The experiments on drug residue demonstrated that the active principle of Chinese medicinal herb could not been mainly detected after the 4th day of medicine blocking up.We studied the purifying effect of water spinach,oenanthe stolonifera,(all of which grew in floating bed) and Microecologics on water quality of Pelodiscus sinensis cultivation,which considered dissolved oxygen, total nitrogen,ammoniacal nitrogen(NH₃-N),nitrate nitrogen(NO₂-N),nitrate nitrogen(NO₃-N),COD,chlorophyll a and so on as the main water quality index.The result demonstrated that total nitrogen,ammoniacal nitrogen(NH₃-N),nitrate nitrogen(NO₂-N),nitrate nitrogen(NO₃-N),COD,chlorophyll a and so on gradually decreased in sequence of group water spinach +oenanthe stolonifera,group water spinach ,group oenanthe stolonifera and group Microecologics ,while dissolved oxygen gradually increased in sequence of group Microecologics ,group oenanthe stolonifera,group water spinach and group water spinach +oenanthe stolonifera;Compared with control group,in the experimental group,the variety and proportion of diatom and Cryptomonas in phytoplankton increased ,however,the proportion of blue-green algae reduced;The composition of phytoplankton turned to Type green alga-diatom from Type green alga-blue-green algae;In zooplankter,the number of wheel animalcule rised;Experimental group could obviously increase the quantity of plankton,accelerate biological cycle,effectively lower the harmful bacteria in water body and increase beneficial flora;Various kinds of physicochemical factors and beneficial flora continuously turned to beneficial aspects during the test;The livability and rateofbodyweightgain of Pelodiscus sinensis in group water spinach+oenanthe stolonifera respectively increased 6.9% and 58.4%;The result showed that using floating bed to cultivate aquatic vegetable could promote the circulation of materials in body of water and strengthen the self-purification of water body.