Study Of Preliminary Investigation And Prevention On Parasitic Diseases Of Farmed Cold Water Fish In Hebei Province

In this paper,preliminary investigation is about the parasitic diseases of cold water fish in Hebei province.In this investigation,the types of pathogenic,hazards and complications,Popular feature were found of the parasitic diseases of cold-water fish to provide a scientific basis for the diagnosis,prediction and prevention about the parasitic diseases.At the same time a preliminary study about the pathogen,prevalence and drug effect of the two new parasitic diseases of sturgeon-white spot disease and glochidia found in the investigation were made.The main results and conclusions are as follows:Through the investigation about the parasitic diseases of fanned cold water fish in Hebei Province,seven kinds of parasitic diseases were found.Among the parasites,the parasitic protozoa had found five types,accounting for about 71%in all the types of parasites what found.It is the main types of parasites that are against the health and safety of farmed Cold-water fish.In this five protozoa,Ichthyophthirius(I.multifiliis) had the widest range of infection and was found in all farms and both species of farmed Cold-water fish.We also found one type of parasitic worms,one type of Glochidium and no other large parasites tapeworm and crustacean.Sturgeon is one of the farmed cold-water fish which has the largest number of farms and the most widely breeding area.All seven kinds of fish parasites have been found on Sturgeon.It infected the largest number of parasites—a total of seven types of parasite.Two new parasitic diseases,white spot disease which was caused by microsporidian (Microsporidium) and glochidia,were found in sturgeon.In the Survey,we found that parasitic diseases that cold-water fish happened has no obviously seasonal characteristics,they generally occured at 5-9 months when the temperature of whater is relatively high.cold water fish infected with smaller types of parasites than common wide temperature fish.parasitic diseases of cold water fish mainly Serious harm to the fish in larvae and juvenile period and infect Saprolegnia at the same time which is Suitable for low temperature.The parasites infected one of the main factors which induced the emergence of saprolegnia. In the study of sturgcon's glochidium,we found that the Pathogenic is glochidia of Anodonta woodiana,they major parasited surrounding the gills,palpus and mouth of sturgeon and might destroy the function of detectding food,caused hunger;At the same time,they also can cause the gills swelling,bleeding,mucus increasing or even death.Since cold water fish need a lower temperature for culture,so glochidium was further happened than other widely temperature fish,but a month-long duration.By the observation and study of the pathogen of Sturgeon'white spot disease, preliminary view is that the pathogen belongs to one of Microsporidia.The pathogen's spore is spherical shape,similar as the Democystidium percae spore.However,the cysts of these two parasites are different.This parasitic disease has no obviously seasonal regularity,at different seasons of the year it may cause sturgeon larvae and juvenile less than 20cm in length a large number to dead.Fry of sturgeon infected with white spot disease may be related to larval fish and juvenile fish skin lower immunity and comprehensive nutrition of artificial feed.Experiments of common disinfective medicine and insecticidal drugs which were used for the treatment of white spot disease shows that:200ppm of formalin what used in a 30-minute medicated bath could make sick sturgeon survival rate up to about 58%,that has the best effection;2ppm povidone iodine and 0.1%of the salt has a certain therapeutic effect, the survival rate is up to 40%.The results are only for reference in the process aquaculture production.In this paper,we only do some preliminary surveys and studies about the major parasitic diseases of farmed cold-water fish in Hebei province.From now on,We should do identification of the biological classification about the pathogen of Sturgeon white spot disease—Microsporidia,and furtherly study of prevention and treatment about pathogenesis and effective Control test to protect and promote the health and sustainable development about Chinese aquaculture industry of cold water fish.