Behavioral and electrocardiographic evaluations in tambaqui (Colossoma macropomum) (Cuvier, 1816) submitted to immersion bath in different concentrations of Tricaine methanesulfonate (MS-222)

Abstract

Research with anesthetics in fish has been extensively explored over the years. The use of Tricaine (MS-222) as an anesthetic is widely known as an ideal anesthetic for fish intended for consumption. It is a synthetic drug derived from benzocaine, however, this drug is not available in the Brazilian market. Tambaqui (Colossoma macropomum) is a freshwater fish natural from the Amazon River and Orinoco River with a very characteristic flavor, it is responsible for a large part of the fish production in the Pará State. This study aimed to evaluate the anesthetic efficacy by monitoring the cardiac function of tambaquis submitted to different concentrations of tricaine: 100 mg.L−1, 150 mg.L−1, 200 mg.L−1, and 250 mg.L−1, for behavioral evaluation during the anesthetic induction and return phase. For the electrocardiogram, the animals were subjected to the same doses in other to record the electrocardiographic data during anesthetic induction and recovery for a period of 10 min. The MS-222 has a potential risk of causing electrocardiographic changes even at the lowest supported doses.