Effects of 2-phenoxyethanol anaesthesia on sheatfish (Silurus glanis L.)

Abstract

The aim of the study was to investigate the acute toxicity of 2-phenoxyethanol to sheatfish, and using the values of haematological and biochemical profiles of blood and histological tissue examinations to assess the effects of the fish exposure to that anaesthetic. The values of acute toxicity of 2-phenoxyethanol to sheatfish were found to be 10minLC50 0.77 ml/l, 10minLC0.1 0.42 ml/l, 10minLC99.9 1.90 ml/l, 96hLC50 0.29 ml/l, 96hLC0.1 0.20 ml/l, and 96hLC99.9 0.41 ml/l. The 10-min exposure to 2-phenoxyethanol at a concentration of 0.30 ml/l caused significantly higher values (<i>P</i> &lt; 0.05) of packed cell volume (PCV), mean corpuscular volume (MCV), glucose (GLU) and albumins (ALB) immediately after anaesthesia. A significant decrease (<i>P</i> &lt; 0.05) in the level of alanine aminotransferase (ALT) and a significant increase (<i>P</i> &lt; 0.05) in the values of mean corpuscular haemoglobin concentration (MCHC) were found 24 h post anaesthesia. Histological examinations showed capillary ectasia of gill filaments immediately after 2-phenoxyethanol anaesthesia. Twenty-four hours after anaesthesia, no ectasia was observed. No histopathological changes were demonstrated in other tissues (liver, spleen, cranial and caudal kidneys) following anaesthesia. The results of examinations suggest that the use of 2-phenoxyethanol at a concentration of 0.30 ml/l does not cause any irreversible damage in sheatfish.