Studies On Different Physical And Chemical Pathogenic Microorganism Eliminating Methods In Culture System Of Apostichopus Japonicus

Apostichopus japonicus has been the main marine breed in Shandong and Liaoning provinces, which has got great economic and societal benefit. The rapid expansion and intensification of sea cucumber farming has led to the occurrences of various diseases and has become one of the limiting factors in the sustainable development of this industry. Skin ulcer syndrome which could cause 90 percent mortality, is the serious disease in both sea cucumber juvenile and adults. It caused several billions economic losses in 2005. So it's very important to find new ways to solve the disease.At present, the study on the diseases in cultured sea cucumber are focus on epidemiology, etiology and tissue pathology, but there are few researches on different physical and chemical pathogenic microorganism eliminating methods in culture systerm of Apostichopus japonicus. In this thesis, we studied the physical and chemical methods on eliminating pathogenic microorganism in order to improve culture techniques of A. japonicus and reduce the frequences of the diseases and keep the sustainable development of this industry.From July of 2006 to January of 2007, we isolated the main pathogenic bacteria of skin ulcer syndrome and do some research on effects of different drugs as disinfectants to exterminate the pathogenic bacteria. It was revealed that all of the disinfectants-Ca(ClO)2, C5H6BrClN2O2, PVP-I, H2O2, C35H67NBr, CaO,had good effects on the pathogenic bacteria extermination. The effective concentrations of the disinfections are 0.2ppm,0.1ppm, 0.25ppm, 0.5ppm, 0.5ppm and 5ppm . Also we studied the acute toxicity of seven disinfections-CaO, TCCA, ClO2, C5H6BrClN2O2, PVP-I, C35H67NBrI, H2O2, on sea cucumber juvenile. The toxicity sequence of the disinfectants to sea cucumber juveniles in a ascending order ranged as CaO