Transportation of silver catfish, Rhamdia quelen, in water with eugenol and the essential oil of Lippia alba

This study investigated the effectiveness of eugenol and of the essential oil (EO) of when used in the transport of the silver catfish (). These investigations involved measurements of blood (pH, O-2, CO2 and HCO3 (-)) and water parameters, survival and ionoregulatory balance. Fish (301.24 +/- A 21.40 g, 28.90 +/- A 1.30 cm) were transported at a loading density of 169.2 g L-1 for 4 h in fifteen plastic bags (7 L) divided into five treatments: control, 1.5 or 3.0 mu L L-1 of eugenol and 10 or 20 mu L L-1 of EO of . The water parameters were measured before (0 h) and after (4 h) transportation. The net Na+, Cl- and K+ losses were higher in fish from the control treatment compared to the other treatments. The O-2, CO2 and HCO3 (-) increased significantly in all of the treatments at the end of the transport period. In conclusion, based on the water (total ammonia nitrogen) and ionoregulatory indicators determined in the present study, our findings indicate that eugenol and the EO of are recommended for use in the transport of this species because these anesthetics apparently reduce stress.