Abstract:
Objective of this study was to evaluate the anesthetic properties of several plant extracts
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 pre-determined stages (Sr S4) were recorded for different concentrations
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 medium
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 comparable
with the recommended criteria for being an effective anesthetic.