“…Consequently, the high costs of manufactured drugs can be avoided. In addition, the tendency to use more environmentally friendly and less dangerous products, together with the limited side effects in animals (Bandeira et al., ), makes the use of these plants an important means to improve the health and nutrition of farmed fish. Extracts and essential oils (EOs) of medicinal plants contain phenolics, polyphenols, alkaloids, quinones, terpenoids and polypeptide compounds, which are natural and effective alternatives to antibiotics, agrochemicals, vaccines and other synthetic compounds (Amaral, Mira, Nogueira, Silva, & Florencio, ; Carbone & Faggio, ; Franz, Baser, & Windisch, ; Guardiola et al., ; Immanuel et al., ; Pês, Saccol, Ourique, Londero, Gressler, Finamor et al., ; Pês, Saccol, Ourique, Londero, Gressler, Golombieski et al., ; Saccol et al., ; Zheng et al., ).…”