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

Table 1 Microsporidia (MS) Facilispora margolisi infections in adult female salmon lice Lepeophtheirus salmonis (F₀) and their F₁ larval progeny as determined by PCR

EXP	Source of F₀ lice	F₀ individual (MS+ / total)		F₁ samples (MS+ / total)
EXP	Source of F₀ lice	Cephalothorax	Egg String	F₀ positive	F₀ negative
1	Chum Salmon	12/20	12/20	11/12 (pools)	0/8
2	Chum Salmon	14/24	13/24	28/39	0/42
3	Atlantic Salmon	25/40	N/A	N/A	N/A
4	Atlantic Salmon	23/40	22/40	2/2 (pools)	0/2
Total		74/124 (60%)	47/84 (56%)	28/39 (72%)^a	0/42 (0%)^a

In experiment (Exp.) 1, each F₁ nauplius and copepodid pool originated from a single F₀ egg string. In Exp. 2, F₁ chalimus II staged lice had developed from pools of MS+ or MS- eggs derived from F₀ females. In Exp. 3, F₁ nauplius and copepodid pools were reserved for in situ hybridizations. In Exp. 4, 40 larval cultures derived from MS+ or MS- F₀ females were divided into 16 pools for each of MS+ and MS- groups, 14 for microarray analysis and 2 for PCR confirmation of F. margolisi (PCR confirmation pools shown in the table). All PCR-positive results in the egg string were also positive in the cephalothorax. ^aTotals only include individuals, not pools