Experimental exposure to low concentrations of Neoparamoeba perurans induces amoebic gill disease in Atlantic salmon

<p>Amoebic gill disease (AGD) is a significant issue in Atlantic salmon mariculture. Research on the development of treatments or vaccines uses experimental challenges where salmon is exposed to amoebae concentrations ranging from 500 to 5,000/L. However, the water concentrations of <i>N. perurans</i> on affected salmon farms are much lower. The lowest concentration of <i>N. perurans</i> previously reported to cause AGD was 10/L. Here, we report that concentrations as low as 0.1/L of <i>N. perurans</i> can cause AGD. We propose that concentrations of <i>N. perurans</i> that reflect those measured on salmon farms should be used for future experimental challenges.</p>