Impact of inducing general anaesthesia with MS‐222 on haematological and biochemical parameters of pikeperch ( Sander lucioperca )

The aim of this study was to determine the impact of MS‐222 on the haematological and biochemical parameters of juvenile pikeperch. The experiment was conducted on fish with body weight of 112.50 ± 13.01 g and body length of 22.5 ± 1.8 cm. The fish were exposed to MS‐222 via immersion at two concentrations (100, 150 mg/L) and for two exposure periods (3, 10 min). Significantly higher values of white blood cells, red blood cells, haemoglobin and haematocrit were noted in all groups of fish from which blood samples were drawn immediately after exposure. After 24 hr, only in group V (100/3/24) did the values of these parameters return to initial values. The analysis of biochemical parameters signalled significant differences in three parameters: glucose, total protein and lactates. Twenty‐four hours after exposure, the values of these three parameters returned to initial levels. Significant differences were also noted in four ion concentrations: potassium, phosphorus, sodium and iron. Twenty‐four hours later, potassium and phosphorus concentrations had returned to initial values, while that of sodium still exhibited significant differences. Twenty‐four hours later, differences were also noted in iron ion concentrations in the groups subjected to the longest exposure or the highest concentration. All of the MS‐222 immersion parameters were effective. However, the smallest changes in the analysed parameters of pikeperch blood were noted in individuals from group I (100/3/0). The current study indicated, however, that longer pikeperch immersion in the anaesthetic solution (>3 min) or applying concentrations exceeding 100 mg/L are not recommended.