Effects of the vertically transmitted microsporidian Facilispora margolisi and the parasiticide emamectin benzoate on salmon lice (Lepeophtheirus salmonis)

This study investigates transcriptomic responses of Pacific salmon lice, Lepeophtheirus salmonis, to infection with the microsporidian Facilispora margolisi and/or exposure to emamectin benzoate (EMB), an antiparasitic agent commonly used in salmon aquaculture. Copepodid larvae derived from individual egg strings were divided into control (0 ppb EMB) and treated (1 ppb EMB) groups, n = 14 pools for each group. Half of each group (i.e. control and treated) was derived from egg strings that tested positive for F. margolisi infection (n = 7 pools/group) and the other half of each group were derived from F. margolisi negative eggs.