Disinfectant Effects of Ultraviolet Irradiation on Fish Pathogens in Hatchery Water Supply
1990
Yoshimizu, Mamoru | Takizawa, Hiroko | Sami, Manabu | Kataoka, Hiroe | Kugo, Tadashi | Kimura, Takahisa
Disinfectant effects of U.V. irradiation were examined on cell suspensions of 5 species of fish pathogenic bacteria, and a punched agar medium disk covered with 10 strains of aquatic fungi and 7 strains of cell free fish pathogenic viruses. 99 .99 % or more of the viable bacterial cells were effected by U.V. treatment of more than 2.2 × 10^3 μW•sec/cm2 U.V. dosage. The hyphae of aquatic fungi showed relatively lower susceptibility to U.V. irradiation, that which inhibited the growth of hyphae was 1.5 - 2.5 × 10^5 μW•sec/cm2. Fish viruses, IHNV, HRV, OMV, CCV and H. salmonis were found to be sensitive to U.V. irradiation, and a 99 % or more infectively decrease (ID99) was 1.0 – 3.0 × 10^3 μW•sec/cm2. Susceptibility of IPNV and CSV were found to be low, ID99 measured 1.0 – 1.5 × 10^5 μW•sec/cm2. The infectivity of IHNV, in virus contaminated river water and IHNV contaminated pond water, measured by the molecular filtration method was 0.56 and 5.6 TCID50/l, respectively U.V. treatment of river water with 10^3 μW•sec/cm2 dosage could prevent an IHN outbreak. Furthermore, U.V. treatment of the hatchery water supply also decreases the visible bacterial counts and fungi infection rates of salmonid eggs.
显示更多 [+] 显示较少 [-]Second Asian Fisheries Forum. 17-22 April 1989. Tokyo, Japan.
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