title: Effects of metomidate anaesthesia or transfer to pur sea water on plasma parameters in ammonia-exposed Atlantic salmon (Salmo salar L) in sea water.
abstract: Atlantic salmon (Salmo salar L) postsmolts weighing 150 ± 53 g were exposed to 14-15 mg l(-1) TA-N (total ammonia-N) in sea water in 1 m(3) tanks for 24h. Blood samples were then taken A) immediately after the fish were netted from the exposure tanks and stunned by a blow to the head; B) 2-20 min after the fish were transferred to 15 l of an anaesthetic solution of metomidate in "ammonia-free" sea water; or C) 2-20 min after the fish were transferred to 15 l of "ammonia-free" sea water. Plasma TA-N level was 18% lower in the anaesthetised fish compared to in the fish sampled directly from the exposure tanks (p ≤ 0.05), and accordingly 16% lower in the fish transferred to pure sea water although this difference was not significant (p = 0.07). Plasma glucose level was higher in the fish transferred to pure sea water than in the fish receiving the two other treatments (p ≤ 0.05), but plasma urea, osmolality, Na(+, Cl-, Ca2+ or Mg2+) levels did not vary significantly between the different treatments. Plasma TA-N level increased with time in the fish in the metomidate solution (p ≤ 0.02).
authors.affiliation: Department of Morphology, Genetics and Aquatic Biology, Norwegian College of Veterinary Medicine, Box 8146 Dep, N-0033, Oslo, Norway.
authors.forename: M B
authors.initials: MB
authors.lastname: Knoph