Exploring the toxicity and anesthetic potential of azaperone in Nile tilapia

Abstract

Nile tilapia (Oreochromis niloticus) is a popular farmed fish species in the world, including Viet Nam. The fish’s fins are hard and pointed, easily causing damage when fishing and transporting. Currently, many anesthetic technologies for aquatic animals have been developed in the world, most notably using chemical baths for fish. Azaperone is known as an anesthetic for livestock and is now used in aquatic animals. The study was conducted to evaluate the anesthetic ability of azaperone on Nile tilapia with size of 20gr/fish using the bathing method and to conduct three main experiments, such as: determining toxicity, evaluating the effect of concentration on induction and recovery time, evaluating the effect of temperature on anesthesia effectiveness. The studied results showed that LC50-96h  (at 29.20C, pH = 7.5-7.9, DO = 6.3mg/l) was 21.14ppm. When increasing the azaperone concentration from 12 ppm to 24ppm, the induction and recovery time decreased, the effective concentration to anesthetize tilapia at 30oC was 20 ppm with induction and recovery times of 153 and 136 seconds, respectively. Temperature effected directly on anesthesia effectiveness. When the temperature reduced to 20oC, the induction and recovery times increased beyond the appropriate range. Consequently, azaperone can be applied in transporting Nile tilapia.