Cortisol as a Stress Indicator in Fish: Sampling Methods, Analytical Techniques, and Organic Pollutant Exposure Assessments

Abstract

Cortisol is the main glucocorticoid released during stress responses in most fish and has been employed to investigate different stressors, including organic pollutants. This review discusses shifts in cortisol concentrations and examines different matrix sampling methods (invasive vs. minimally or non-invasive) and the main analytical cortisol determination techniques (immunoassays and liquid chromatography-tandem mass spectrometry). Assessments on organic pollutant exposure in fish and associated adverse effects are also discussed. Studies in this regard may aid in identifying organic pollutant toxicological modes of action, mechanistic response, toxicokinetics, and toxicodynamics, as well as pollution sources and associated health risks in fish, ultimately aiding in the development of effective management strategies to mitigate the impacts of organic pollutants on fish populations and their associated ecosystems.

Potentials of Gynura procumbens to modulate chronic stress and immunological responses in Oreochromis niloticus

“…A cortisol assay was first carried out to see if the hydrocortisone supplied to the fish effectively and efficiently stressed the fish [ 31 ]. We required to understand how cortisol is produced in the body and how long it is active in order to fully comprehend the findings.…”

Fish Responses to Alternative Feeding Ingredients under Abiotic Chronic Stress

“…However, cortisol cannot be just related to negative stressors; not all cortisol fluctuations indicate distress. Thus, it is essential to differentiate the baseline from a standard range of stress-related concentrations [ 29 ]. Cortisol is a hyperglycemic hormone as it causes the elevation of plasma glucose, providing fish with energy to escape or cope with an adverse situation [ 47 ].…”

“…Abiotic factor [28] Chemicals (insecticides, pesticides), dissolved oxygen, pH, temperature Abiotic factor [11] Temperature, chemical contamination, photoperiod, salinity Abiotic factor [29] The negative impact of chronic stress caused by abiotic factors includes (1) somatic growth, (2) metabolism, and (3) oxidative stress. A search of scientific studies on chronic stress in fish due to abiotic factors was performed to understand how dietary interventions modulate this condition.…”

Effects of vitamins C and E on semen quality and reproductive hormones in yellow mystus (Hemibagrus spilopterus)

“…Cortisol is commonly used as an indicator of stress and supplementation with Vit C and Vit E can assist fish in maintaining normal stress indicators when subjected to stressful conditions (Ortuño et al, 2003). Furthermore, cortisol itself is closely linked to many of the adverse consequences of chronic stress, including effects on growth, reproduction and the immune system (Lemos et al, 2023). Consequently, the extent of cortisol elevation following exposure to a standardized stressor has been adopted as a trait of physiological significance on which a selection procedure may be based.…”