The aim of this study was to analyze the survival of fingerlings of Rhamdia quelen to different concentrations of salinity (common marine salt and seawater). Salt is used in the treatment of some fish diseases and to reduce the stress of handling and transport. Fingerlings (1.68 ± 0.87g) were kept in a 1400l tank with running freshwater at 23-25°C, for 3 to 7 days, being fed daily. Later groups of 50 specimens were transferred to 250l tanks with a water re-use system. The water concentration was 8.0, 9.0, 9.25, 9.5, or 10.0g/l common marine salt or 10.0, 12.0, or 14.0‰ artificial seawater. Survival was observed over a period of 96h. The control group was maintained in the same conditions, but with salinity of 0‰. There was no mortality and change of behavior in the groups exposed to 8g/l common marine salt and to 10‰ seawater. The group exposed to 9g/l common marine salt also did not show mortality, but there was an alteration of the feeding behavior. Higher concentrations of common marine salt or seawater increased mortality and provoked changes in the feeding behavior. Since R. quelen tolerated common marine salt up to 9g/l for 96h, salt can be tested to prevent or treat diseases and to reduce the stress of transport.
common salt; teleost; fish culture; seawater
