سال انتشار: ۱۳۸۷

محل انتشار: اولین کنگره بین المللی مدیریت بهداشتی و بیماریهای آبزیان

تعداد صفحات: ۱

نویسنده(ها):

K Khabir – Faculty of Veterinary Medicine, Shahrekord University
A Khaghani –
F Abasi –
M Rashidi –

چکیده:

Objective: Anaesthetics play an important role in both fisheries research and aquaculture, being used to facilitate various handling procedures, such as weighting, sorting, and collection of spawning material, tagging, or veterinary treatment. Clove oil, containing the active ingredient eugenol, has been reported to be effective on several species of fish. Its main advantages lie in its low cost, and its relative safety to both fish and humans. The objective of the presently reported study was to establish the lowest effective concentration of clove oil for the goldfish, Carassius auratus, and safe working ranges for the anaesthetic.
Method & Materials: The fish were acclimated for 10 days in 80-liter aquariums prior to trial, in aerated tap water at 21 ± ۱°C. 30 goldfish (with average weight of 100 ± ۹٫۳ g) were exposed to the concentrations of 20, 40, 60, 80 and 100 mg/l of clove oil (80.8% eugenol). The onsets of individual phases of anaesthesia and recovery rates were studied. In experiment 1 the fish were held in the anaesthetic bath until the lack of responses to handling was observed and in experiment 2 until the fading of ventilation.
Results & Conclusion: Clove oil at the concentrations ranging from 20 to 100 mg/l induced general anaesthesia. The lowest effective concentration is the concentration that produces general anaesthesia within 3 min and allows the recovery within 10 min. The term safe exposure time denotes the part of exposure when the fish breathe regularly, without signs of oxygen deficiency. The lowest concentration causing general anaesthesia with an average induction time below 3 min was 40 mg/l. Recovery was concentration-independent and lasted for about 3 min (experiment 1). An increase in the concentration shortened the time of ventilation during anaesthesia and prolonged the recovery (experiment 2). Clove oil is a potent anaesthetic for goldfish, the safest and most effective at the concentrations of 40-60 mg/l. Therefore, those solutions should be used, in the aquaculture practice, when the procedure requires more than 5 min of the exposure to the anaesthetic.