The Israeli Journal of Aquaculture - Bamidgeh 55(4), 2003
The 7th Annual Dan Popper Symposium


THE EFFECT OF ANESTHETICS ON STRESS AND
THE INNATE IMMUNE SYSTEM IN THE GILTHEAD SEA BREAM,
SPARUS AURATA


Keren Bressler and Benny Ron*

Israel Oceanographic and Limnological Research, National Center for Mariculture, PO Box 1212, Eilat, 88112, Israel


Abstract

Anesthetics are frequently used in fisheries research and aquaculture to minimize stress response and prevent its negative impact on performance. Nevertheless, severe anesthesia may itself induce a stress response in fish that can lead to immunodepression and increase susceptibility to disease. In the present work, two anesthetics that are commonly used in aquaculture, clove oil (0.445 mM) and benzocaine (0.225 mM), were tested to observe their effects on the stress responses and innate immune system activity of the gilthead sea bream (Sparus aurata).

Both anesthetics increased blood glucose and serum cortisol levels. In addition, benzocaine depressed lysozyme activity, production of reactive oxygen species and pinocytosis, while these results were not observed in fish anesthetized with clove oil. Benzocaine had a negative effect on the humoral and cellular responses. Clove oil, however, did not exert any immunodepressive effect on the innate immune system, suggesting that clove oil is the preferred anesthetic for sea bream aquaculture and research.

E-mail: ronbenny@agri.huji.ac.il


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