Applying new formulated herbal anesthetic comparing to tricaine methanesulfonate (MS-222) in beluga (Huso huso)

Applying anaesthetic agent is recommended in aquaculture during fish handling specially tagging. However, it should be noted that anesthesia itself is likely to induce stressful condition due to its improper and high concentration. By means of nanoemulsions, drug delivery improves which in turn contributes to fewer amounts of pharmaceutical agents’ usage. In this research, nanoemulsions of clove oil (NCL) and lemonbeebrush (NLB) were used to develop the anesthetic efficacy and reduce the concentration needed for anesthesia in Huso huso (mean weight: 1115 ± 242.25 g) as an endangered species. Based on the results, anesthesia induction time (s) of stage 3 & 4 was significantly decreased in NCL and NLB when compared to MS-222 (p<0.05). NCL treated beluga were induced stage 5 anesthesia much quicker than NLB and MS-222. In contrary, recovery time did not show significant difference among treatments (p>0.05). Among measured biochemical factors, lactate had the highest value in NCL group during anesthesia (p<0.05). In contrast, lactate level had highest level in NLB, 24h post anesthesia (p<0.05). NLB and NCL produced higher non-specific immune (Lysozyme and ACH50) enhancements at 0 and 24h post anesthesia. Furthermore, results showed that MS-222 induced increased serum cortisol levels (p<0.05). Cortisol and glucose were not depressed by NLB and NCL, suggesting that these anesthetics are safer anesthetic for Huso huso as it does not cause immune depression in anesthetized fish.