Study on the Resistance to Vibriosis in Induced Triploid Ayu Plecoglossus altivelis

Abstract

The resistance to vibriosis of triploid ayu induced by cold shock and normal diploid ayu were compared by the susceptibility to Vibrio anguillarum and the potency of vibriosis vaccine as parameters. It was demonstrated by immersion challenge experiments that there was no difference in susceptibility to V. anguillarum between the two groups. The artificial challenges with V. anguillarum were also attempted at 1, 2, 3 and 8 weeks after an immersion vaccination. The relative of percentages survival in triploid was slightly lower than that in diploid, but the difference was not sigrificant. From these results, it is suggested that the resistance to vibriosis in triploid ayu is quite similar to that of normal diploid ayu.