Indicadores de estresse em curimba (Prochilodus lineatus) (Valenciennes, 1836) em escada para peixes, no Alto Rio Paraná, Brasil

Abstract

Stress is an adaptive component that allows the fish to deal with various stressful events that occur during the life cycle of fish, such as the reproductive migration that demands physical efforts. The aim was to assess whether the steps for implementation to fish in the reservoir dam is promotes stress in curimba (Prochilodus lineatus). Adult fish species were sampled in March 2015 at three sites in the Hydroelectric Powerplant of Porto Primavera, Upper Paraná River, Brazil: downstream, the fish ladder and upstream of the dam, totaling 48 individual. Variations in body weight, standard length, and determination of plasma concentrations of cortisol, glucose, lactate, choloride and hematocrit they were analyzed in relation to gender and local sampled. The body weight and standard length presented comparable values for each location between genders, but the averages of females were significantly higher. Significant increase in plasma levels of glucose and lactate were observed but without significant changes in cortisol, chloride levels, as well as in hematocrit. The intense exercise of the fish by the transposition of fish ladder represented moderate stressor, without causing harmful effects to these animals, since the recovery of fish at the upstream from the dam. These results are deepening about the physiology used as a tool for conservation by providing knowledge and subsidies for the conservation and management of migratory species.