EUGENOL AS ANESTHETIC FOR Brycon hilarii

摘要

Anesthetic products are frequently employed during fish handling practices; however, the correct doses of the various chemicals for different species are still unknown. One of these newly farmed species in Brazil is known as piraputanga, belonging tothe Brycon genus and Briconinae family. This family comprises close to 40 species, reported in a small number of studies in the literature. This species is endemic to the Parana and Paraguay River basins and belongs to the group of the great Neotropicalmigrants. It is pursued by both local small fishing communities, for sports fishing due to its aggressive behavior when caught, and is considered the main species of touristic interest in the area of Bonito, MS, Brazil. Anesthetics are used in animals tolower their metabolism during physiological interventions and some culture procedures, so they become less susceptible to ailments caused by inadequate handling techniques. This study determined the ideal concentrations of eugenol as anesthetics used inBrycon hilarii juveniles. Seven eugenol concentrations (50.0, 100.0, 150.0,200.0,250.0,300.0 and 350 mg.L"1) were evaluated in order to assess the induction time to anesthesia, and a control group submitted to the same handling process without sedation.For each treatment, eight fish were randomly selected (n = 8) and individually exposed to each concentration. The water in the experimental tanks was renewed at the end of each concentration test. The fish were transferred to anesthetic-free tanks to recover, and the time needed to return to normal activity was recorded. The times required for the display of the behavioral patterns described in Table 1 were monitored using a digital chronometer.