Effect of clove (Eugenia aromatica) powder anaesthetic on some haematological parameters in hybrid catfish (Heterobranchus bidorsalis x Clarias gariepinus ) juveniles

Abstract

This study was designed to investigate the efficacy of clove powder as anaesthetic and its effect on some haematological parameters of hybrid (Heterobranchus bidorsalis ♀ x Clarias gariepinus ♂) juveniles. Different concentrations of 80, 90, 100, 110, 120, and 130 mg/L were exposed to 108 healthy fish of mean weight 20.38 ± 3.30 g and total length 14.33 ± 2.50 cm for 30 min at the Fisheries Laboratory CRUTECH, Obubra campus. The fish behaviour was observed, the time to become completely immobilized and recovery from anaesthesia were recorded at the various stages with a stopwatch. Fish that were exposed to less than 100 mg/L clove powder reached Stage 3, but did not reach Stage 4 (complete immobilization) during the 30 min evaluation period. At the highest concentration of clove powder of 130 mg/L fish are anaesthetized (Stage 4) in less than 3 min and regained their normal position in more than 24 min. Fish exposed to higher concentrations above 100 mg/l took longer time to achieve recovery. The time to achieve recovery had a positive response to dose. The value of Red blood cell (RBC) shows a significant decrease while White blood cell count (WBC) with increase in the concentration of clove powder, then the haematological indices showed a significant increase in the values of (MCV) and Mean corpuscular Haemoglobin (MCH) while MCHC was not significantly different from the control (p < 0.05). The mean values of lymphocytes significantly increased whereas, neutrophil, monocytes, basophil, and eosinophil did not differ from the control. Result from this study suggests that, the use of clove powder at the concentration of 120 mg/L will completely induced deep anaesthesia without significant changes in the haematological parameters. Key words: Clove powder, anaethesia, recovery, haematological parameter, catfish hybrid