Table 1.
Plasma Na+, Cl−, osmolality and cortisol in Atlantic salmon (Salmo salar) on Day 30, 28 days post infection with salmon lice (Lepeophtheirus salmonis)
| Parameter | Salmon lice infected | Control | P value * | P value ** | |
|---|---|---|---|---|---|
| Normal | Moribund | ||||
| N per category | 35 | 10 | 45 | ||
| Na+ (mmol L−1) | 190.6 ± 3.8b | 233.9 ± 4.9a | 169.3 ± 0.5c | 0.0276 | 0.0000 |
| Cl− (mmol L−1) | 167.6 ± 3.9b | 213.2 ± 4.6a | 140.3 ± 0.5c | 0.0125 | 0.0000 |
| Osmolality (mOsm kg−1) | 380.8 ± 7.2b | 469.9 ± 10.9a | 347.4 ± 1.8c | 0.0467 | 0.0000 |
| Cortisol (ng ml−1) | 193.8 ± 27.4b | 470.7 ± 26.7a | 86.4 ± 10.0c | 0.1826 | 0.0000 |
N = 45 per treatment group (15 per tank). Some of the infected fish were moribund at the terminal sampling.
*Number in italic and bold indicates a significant difference (two-way nested ANOVA, P < 0.05) between ‘Salmon lice infected Normal’ and ‘Control’ fish.
**Number in italic and bold indicates a significant difference (Kruskal–Wallis ANOVA, P < 0.05) between ‘Salmon lice infected Normal’, ‘Salmon lice infected Moribund’ and ‘Control’ fish. Different lowercase letters indicate significant differences.