3.2 Preliminary Anesthetic Activity Test in Bighead Catfish
Anesthetization was carried out on polyvinyl vessel with 20 L of
an anesthetic solution. A total 120 fish were divided into 12 groups of
10 fish each. Six groups of fish were anesthetized at 25 ppm
concentration of 6 compounds (1-6). Other six groups were also
anesthetized at 50 ppm concentration of 6 compounds (1-6).The
range stages of anesthesia and recovery process with eugenol
derivatives experiment in Bighead catfish were summarized in Table
2 and 3 respectively. The purposes of this experiment was to
examine the anesthetic effect, loss of equilibrium to stage 4 of
anesthesia (Table 2), which is defined as the stage at which a fish is
unable to recover and maintain an upright position in the water.
Recovery process of equilibrium was taken immediately after fish
reach the anesthesia stage 4 by gently transferred into acclimation
tank for recovery by netting. The recovery process refers to stage 4
recovery (Table 3), and is defined as the stage at which a fish is able
to maintain an upright position in the water without subsequent loss
or partial loss of equilibrium. The recovery of the fear or fright
response refers to the stage at which a fish beings to show a
response to external visual or mechanical stimuli (stage 4, Table 3),
and is usually behaved from the stimulus [10].