We investigated a group of Rhamdia quelen females during their entire first reproductive cycle and beginning of the 2nd cycle by evaluating the stress response at different phases of gonadal maturation. In mammals, including humans, pubertal development modulates stress response reactivity due to the maturation of the neuroendocrine stress axis. These shifts in the stress reactivity were also detected in salmonid fishes. This effect comes from changes in the sensitivity of the stress axis glands or in the capacity of the adrenal tissue to synthesise glucocorticoids. Here, for the first time, we show that similar to mammals and salmonid fishes, pre-pubertal female R. quelen exhibit a protracted stress response compared to adult fish, pointing to puberty as a key event on HPI axis modulation.