Anesthetic effect of ethanol, MS۲۲۲ and cold maintenance on freshwater crayfish (Astacus leptodactylus)

Freshwater crayfish from the Aras Dam are considered one of the country's high-value fishery export resources. Freshwater crayfish are exported live and at low temperatures. Limited studies have been conducted on their welfare and the use of anesthetics in stressful situations such as handling, cooking, manipulation, sampling, and transportation. The present study was conducted to determine the effective dose and time of anesthesia induction and recovery time using different levels of MS-۲۲۲ (levels ۰, ۵۰, ۱۰۰, ۲۰۰, ۴۰۰, ۸۰۰ and ۱۲۰۰ mg/L), ethanol (levels ۰, ۵۰, ۱۰۰, ۲۰۰, ۴۰۰, ۸۰۰, ۱۲۰۰ and ۱۶۰۰ mg/L) and cold (temperatures ۴, ۶, ۸ and ۲۵°C as control) in freshwater crayfish (Astacus leptodactylus). In this study, the duration of anesthesia induction and recovery time of freshwater crayfish were investigated with the aim of determining the appropriate anesthetic concentration for young crayfish weighing approximately ۲۰±۳ grams. The results of the present study showed that the use of high levels of MS-۲۲۲ was not effective in anesthetizing freshwater crayfish. The use of ethanol at high levels (۳۰%) was also able to anesthetize crayfish in a short time, but at low levels this process required a long time. The results also showed that a low temperature of ۴°C had the shortest induction time and the fastest recovery from anesthesia compared to MS-۲۲۲ and ethanol. Therefore, the use of ethanol due to high stress induction and MS-۲۲۲ due to high price and low performance in freshwater crayfish anesthesia is not recommended.

کلیدواژه ها:

Anesthesia ، MS-۲۲۲ ، Ethanol ، Cold ، Freshwater crayfish