Survey of Experimental Contamination to Ichthyophthirius multifiliis in Cultural Rainbow Trout Consequently Vaccination with Aquavac garvetil

Abstract

The rainbow trout is the only cold water fish in Iran which has specific economic importance. One of the major bacterial diseases among the rainbow trout is streptococcosis which can be controlled through aquavac garvetil vaccine. It has been shown that this vaccine has stimulation effects on specific and non-specific immune system in the fish. So the aim of this study was determination of Ichthyophthirius experimental infectious in rainbow trout after aquavac garvetil vaccination. In this study, 2000 fish (1g) randomly selected and ten infected fish by Ichthyophthirius added to pool after 15 days. After 60 days, fishes randomly divided in control and treatment groups. In treatment group, vaccination was done in two stages. First stage in day 67 which fish were sunk in aquavac garvetil vaccine and in second stage vaccine were administrated orally in day 127. In control group, vaccine were not used. After one month, in both groups, 500 fish randomly were selected and anesthetized, after wet mount preparation the numbers of parasites were counted. Mean of number of parasites compared in control and treatment groups. Results showed that in treatment group after vaccination the number of parasites significantly decreased (p<0.05) compared with control group. This effect of aquavac garvetil vaccine is probably via stimulating effect of this agent on nonspecific immune system in fishes. However study of the mechanism of this vaccine in decreasing of Ichthyophthirius infections needs to more investigation.