Fish anaesthetic properties of some local plant material

Abstract

Objective of this study was to evaluate the anesthetic properties of several plant ex­ tracts in common carp (Cyprians carpid). Extractions were made by grinding 50 g of plant material with 500 ml of water followed by crushing and filtering. Induction times of anesthesia to four predetermined stages (Sr S4) were recorded for different concen­ trations of plants extracts. When fish lost the total equilibrium (S4), if was placed in a fresh water tank and the recovery time was recorded. Each concentration of the plant extract was tested in ten replicate fish. Clove (Eugnia carioplyllum), Clotalaria (Clotalaria sp), KalaweB (Berris scandens) and Kukuru extracts showed high to me­ dium level of anesthetic properties. Clove gave the best induction and recovery times. At 3 ml plant extract/L, fish attained S4 within 5.5 minutes and recovered within 15 minutes. Even though clotalaria at 2.5ml/L induced S4 within 4.3 minutes, the recovery time was 64 minutes. KalaweS had a narrow effective range and acted fast. At 2 ml/L fish attained S4 within 8.7 minutes and recovered in 43 minutes. At 3.75 ml/L Kukuru had 20 minutes induction and 60 minutes recovery time. Welan and Medella (Barrigtonia racemosa) showed some anesthetic properties but were less effective due to longer induction and recovery times. Thiththawel (Anamirla coculus), Thala (Corypha ambraculifera) and Daluk (Euphorabhia antiqurum) showed no anesthetic properties but were toxic. It is concluded that anaesthetic properties of clove are com­ parable with the recommended criteria for being an effective anesthetic.