The aim of this study was to evaluate the response of eugenol, propofol, isoflurane and lidocaine on physiological and anaesthesiologic variables of Cheirodon interruptus, the most widely used baitfish in Argentina. Six groups were formed: 25 mg/l eugenol, 50 mg/l eugenol, 300 mg/l lidocaine, 0.2 mg/l isoflurane, 0.4 mg/l isoflurane, and 5 mg/l propofol. The tests are carried out with water at a temperature of 18.03±2.1 °C, pH 6.87±0.18, dissolved oxygen 6.73±0.05 mg l-1 and conductivity 3.74±0.04 μS cm-. The initial weight (1.6±0.4 g) and total length (5.1±0.4 cm) were statistically similar between groups. The results indicate that eugenol and isoflurane meet the requirements that a good anaesthetic for use in fish should meet. For propofol and lidocaine, it is considered necessary to review the dosage to adapt its use in C. interruptus due to the long recovery time. The fish tr...

The aim of this study was to evaluate the depressing activity of etomidate at concentrations of 1 and 2 ppm/L in rainbow trout from an intensive breeding system in Córdoba, Argentina. The use of the anaesthetic, regardless of the dose, produced a reduction in respiratory frequency between 61 and 66% in anaesthesia compared to the basal respiratory frequency (p<0.05). The times of partial and total loss of equilibrium and in anaesthesia were statistically lower (p<0.05) at the dose of 2 ppm/L, while the recovery time did not present significant differences (p>0.05) between groups. The concentrations used induced a dose-dependent state of anaesthesia that allows the manipulation of the fish without adverse effects that compromise the life of the fish.