en عمومى General پژوهشي Research <span style="font-size:11pt"><span style="line-height:120%"><span style="font-family:Calibri,sans-serif"><span class="Authorsname" new="" roman="" style="font-family:" times=""><span lang="TR" style="font-size:12.0pt"><span style="line-height:120%"><span style="color:black">Freshwater crayfish from the Aras Dam are considered one of the country&#39;s high-value fishery export resources. Freshwater crayfish are exported live at low temperatures. Limited studies have been conducted on the welfare and use of anesthetic agents in stressful situations such as handling, cooking, manipulation, sampling, and transportation. In the present study, the efficacy of 0, 50, 100, 200, 400, 800, 1200, and 1600 mg/L of clove essential oil (Pars Iman Daru, PI-222) as an anesthetic for freshwater crayfish (<i>Astacus</i> <i>leptodactylus</i>) was evaluated.</span></span></span></span><span lang="TR" style="font-size:12.0pt"><span style="line-height:120%"><span new="" roman="" style="font-family:" times=""><span style="color:black"> <span class="Authorsname" new="" roman="" style="font-family:" times=""><span style="line-height:120%">Also, 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 20 &plusmn; 3 grams.</span></span> <span class="Authorsname" new="" roman="" style="font-family:" times=""><span style="line-height:120%">The results of the present study showed that the appropriate concentration of clove essential oil for anesthesia of freshwater crayfish in Aras Dam, considering the reduction in the time to reach stage 4 of anesthesia and also a significant reduction in the time to recover from anesthesia, was 1200 mg/L. According to the results of the present study, clove essential oil at a concentration of 1200 mg/L can be used as a safe and inexpensive anesthetic in freshwater crayfish for anesthesia and stress control in manipulations such as sampling and surgery.</span></span></span></span></span></span></span></span></span> Anesthesia, Clove essential oil, Freshwater crayfish, Astacus leptodactylus 29 39 http://injvr.com/browse.php?a_code=A-10-85-1&slc_lang=en&sid=1 M. Seidgar seidgar2011@gmail.com 10031947532846001567 10031947532846001567 Yes National Artemia Research Center, Iranian Fisheries Science Research Institute, Agricultural Research, Education and Extension Organization, Urmia, Iran R. Jalili re.jalili@gmail.com 10031947532846001568 10031947532846001568 No National Artemia Research Center, Iranian Fisheries Science Research Institute, Agricultural Research, Education and Extension Organization, Urmia, Iran S.S. Mirzargar zargarm@ut.ac.ir 10031947532846001569 10031947532846001569 No Department of Aquatic Animals Health and Diseases, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran