AUTHOR=Ruiz Nuria , García-Meilán Irene , Khansari Ali Reza , Teles Mariana , Pastor Josep , Tort Lluís 

TITLE=Repeated hypoxic episodes allow hematological and physiological habituation in rainbow trout

JOURNAL=Frontiers in Physiology

VOLUME=Volume 15 - 2024

YEAR=2024

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2024.1289903

DOI=10.3389/fphys.2024.1289903

ISSN=1664-042X

ABSTRACT=Under climate change the increase of temperature in aquatic environments may induce oxygen depletion. In extreme cases, low oxygen may become a limiting factor for fish, thus generating stress. In addition, consecutive hypoxic episodes may complicate the recovery of individuals and hinder their ability to modulate physiological and biochemical responses to maintain homeostasis.Thus, the aim of this study was to determine the hematological and physiological responses of rainbow trout under a condition of repeated hypoxic and manipulation stress at three different time points. Every hypoxic episode consisted in exposing the fish to low dissolved oxygen concentrations (2 mgO 2 /L for 1 hour). Following the exposure, the fish were allowed to recover for 1 hour after which fish were sampled to investigate hematological and physiological parameters.The results showed a pattern of habituation reflected by values of hematocrit, hemoglobin and mean corpuscular volume, indicating a certain ability of rainbow trout to resist this type of repeated hypoxic events, provided that fish can have some recovery time between the exposures.