Fish are an important resource for humans, providing food, economic support, and ecological services. However, rising global temperatures and subsequent increases in their habitat water temperature, pose a significant challenge. We conducted a systematic review to understand the biochemical responses of thermal stress on fish. Stress can be acute (rapid exposure for a short duration) or chronic (repetitive long-term exposure). Stress responses occur at neurotransmitter and hormonal levels, progressing to peripheral and organism-wide effects. Prolonged stress leads to reduced growth, reproductive impairments, heightened infection susceptibility, and mortality. Elevated temperatures serve as abiotic stressors, triggering biotic stress responses. Fish employ strategies to cope with thermal stress, including altering gene expression, metabolite profiles, cellular signaling, and enzyme activity. Cumulative effects of thermal stress induce oxidative stress, causing cell death, organ failure, and mortality. Stressors increase the energy demand, prompting changes in hormonal, enzymatic, and biomolecular responses. Cortisol alters gene expression, stimulating glucose synthesis (gluconeogenesis). Other hormones (thyroid hormones, epinephrine, norepinephrine, insulin, glucagon) also play roles in the thermal stress response. Enzymes involved in metabolic pathways have optimal temperature and pH ranges altered by thermal stress. Heat shock proteins and warm acclimation proteins act as protective mechanisms by preserving the structural integrity of proteins, which is crucial for maintaining proper functionality and cellular responses. Further research is needed to expand on these molecular mechanisms to evaluate proper mitigation strategies.
Primary Language | English |
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Subjects | Hydrobiology |
Journal Section | Review |
Authors | |
Publication Date | March 29, 2024 |
Submission Date | August 25, 2023 |
Published in Issue | Year 2024 |
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