Anti-stress nutrition: A vital strategy for profitability and health in aquaculture

Modern aquaculture operates within an environment of persistent challenges, where stress has emerged as one of the most critical adversaries to productivity. Factors such as transport, handling, and fluctuations in water quality expose aquatic animals to risks that compromise their growth, immunity, and survival.

A recent review published in the prestigious journal Reviews in Aquaculture, conducted by researchers from the Institute of Feed Research of the Chinese Academy of Agricultural Sciences (CAAS), delves into a revolutionary concept: “anti-stress nutrition.”

This approach transcends merely meeting basic requirements; it proposes using diet as a therapeutic and preventive tool to maintain homeostasis and organism health under adverse conditions.

Key conclusions

For producers and technicians, the study highlights four fundamental pillars:

• The Multifactorial Nature of Stress: Animals face environmental, physical, and biological stressors simultaneously, demanding comprehensive nutritional strategies.
• Functional Nutrients: Specific amino acids, vitamins, and minerals are crucial for regulating cortisol and potentiating antioxidant capacity.
• The Gut-Brain Axis: Modulating microbiota through prebiotics and probiotics is essential for managing the stress response.
• Precision Nutrition: The future of the industry lies in personalized diets tailored to the species, the type of stress, and the developmental stage.

Physiological Impact of Stress in Culture

The study defines stress as a series of non-specific physiological responses to extraordinary stimuli. While an acute response can be adaptive, chronic stress leads to metabolic disorders, immunosuppression, and tissue damage.

Researchers categorize stressors into four groups:

1. Environmental: Temperature, salinity, ammonia, dissolved oxygen, and pollutants (microplastics, heavy metals).
2. Physical: Handling, transport, high stocking densities, and noise.
3. Biological: Pathogens (viruses, bacteria, parasites) and intraspecific conflicts.
4. Anthropogenic/Natural: Natural disasters or human interventions that modify the habitat.

The response to these factors activates complex neuroendocrine axes, releasing hormones such as cortisol. This triggers an energy trade-off: resources intended for growth are reallocated to defense mechanisms, directly affecting the Feed Conversion Ratio (FCR) and profitability.

The Role of Essential Nutrients in Mitigation

Under stress conditions, nutritional requirements shift drastically. The diet must not only sustain growth but also repair damage and reinforce the immune system.

Functional amino acids

Tryptophan, taurine, and glutamine are vital. Tryptophan modulates serotonin, inhibiting cortisol and improving feed intake under stress. Meanwhile, taurine and glutamine have been shown to enhance osmoregulation and antioxidant capacity in species such as rainbow trout and tilapia.

Vitamins and minerals

Vitamins C and E are indispensable due to their potent antioxidant action against stress-induced free radicals. Regarding minerals, zinc and selenium act as crucial enzymatic cofactors for detoxification. The study emphasizes that dietary supplementation of these micronutrients is safer and more effective than direct application in the water.

New allies: Conditionally essential nutrients

A valuable contribution of the study is the identification of “conditionally essential nutrients”: compounds that the animal synthesizes, but not in sufficient quantities, during situations of high demand.

• Plant Extracts: Compounds such as curcumin and Astragalus polysaccharides offer superior immunostimulant properties.
• Fatty Acids: An optimal DHA/EPA (long-chain fatty acids) ratio is critical for modulating inflammation and disease resistance.
• Alpha-Lipoic Acid and Alpha-Ketoglutarate (AKG): These molecules optimize energy metabolism. Alpha-lipoic acid has been shown to alleviate oxidative damage and chelate heavy metals.

Gut microbiota and research methods

The intestine acts as a key immunological barrier. Since stress often causes dysbiosis (alteration of the microbiota), the use of prebiotics (MOS, FOS) and probiotics (Bacillus, Lactobacillus) is fundamental. The discovery regarding Cetobacterium somerae, a vitamin B12-producing bacterium that improves viral resistance in fish, is particularly noteworthy.

Regarding research, the article underscores the transition from classical methods toward “omics” technologies (transcriptomics, metabolomics), enabling an understanding of the molecular mechanisms of anti-stress nutrition. Furthermore, the potential (and ethical challenges) of gene editing with CRISPR/Cas9 is mentioned.

Future perspectives

Although science has advanced, gaps remain in the study of mollusks and amphibians. The CAAS researchers suggest for the future:

• Developing experimental models that simulate multiple simultaneous stressors.
• Deepening precision nutrition adjusted to the environment.
• Innovating with technologies such as nano-encapsulation to improve bioavailability.

Implementing these strategies is an essential step toward a more sustainable and efficient aquaculture in the face of global climate change.

Contact
Zhigang Zhou
Sino-Norway Joint Lab on Fish Gastrointestinal Microbiota, Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing, China
Email: zhouzhigang03@caas.cn

Reference (open access)
Zhang, J., Ding, Q., Lou, R., Zhang, Y., Yao, Y., Yang, Y., Zhang, Z., Ran, C., & Zhou, Z. (2026). Stress Nutrition in Aquatic Animals: From Definition to Practice. Reviews in Aquaculture, 18(1), e70091. https://doi.org/10.1111/raq.70091

Milthon Lujan

Editor at the digital magazine AquaHoy. He holds a degree in Aquaculture Biology from the National University of Santa (UNS) and a Master’s degree in Science and Innovation Management from the Polytechnic University of Valencia, with postgraduate diplomas in Business Innovation and Innovation Management. He possesses extensive experience in the aquaculture and fisheries sector, having led the Fisheries Innovation Unit of the National Program for Innovation in Fisheries and Aquaculture (PNIPA). He has served as a senior consultant in technology watch, an innovation project formulator and advisor, and a lecturer at UNS. He is a member of the Peruvian College of Biologists and was recognized by the World Aquaculture Society (WAS) in 2016 for his contribution to aquaculture.