Evaluation the Ozone Treatment to Control the Infection of Saprolegniasis in Cyprinus carpio L.

Abstract

The objective of present study is to set up an alternative method of controlling of saprolegniasis, in Cyprinus carpio L. using ozone. For this purpose, six different treatments were applied of 120 fish (20 fish/treatment), of which three infected with Saprolegnia spp. (2×104 zoospors/l) and were treated with ozone (O3) in concentrations of 0.25, 0.50 and 0.75 mg l-1 (1hour), one reference treatment with formalin (0.15 ml l-1, 30 min), two treatments one as positive control (infected with Saprolegnia spp. without disinfectants) and one as negative control without any disinfectants. After 14 days of treatment with ozone and formalin, blood samples were collected from fish for hematological, biochemical and Immunological tests. Survival rate was also studied. Considerable changes have been recorded in the mean values of blood indices. RBCs count and Hemoglobin content, were found significantly increased (p<0.05) in all ozone treatments compared to C- group. Total protein and globulin were significantly increased (p<0.05) in all ozone and formalin treatments in comparison to positive and negative groups (C- and C+). Albumin showed a significant decrease (p<0.05) in all ozone and formalin treatments relative to C+ and C-group. The results of respiratory burst activity (measured by Nitro blue tetrazolium reduction assay) showed significantly different (p<0.05) in all ozone and formalin treatments respectively compared to control groups (C+ and C-); Highest respiratory activity was observed in ozone treatment at 0.50 mg/l. Among Ozone treatments 0.50 mg l-1 showed the highest survival rate (90%) followed by formalin treatment (80%). Survival rate of the control group (without disinfectant) was 20% and there was a significant difference (P<0.05) with other treatments. It was obvious that the obtained results were highly suggestive for the efficiency of ozone as an efficient antifungal disinfectant for fish.