FISH HEALTH

Strengthening the fish natural defences is key to the future of aquaculture health

China, 5 January 2026 |

Unlike mammals, fish rely heavily on innate immunity to defend themselves against pathogens, making it one of the most effective strategies for health management in aquaculture, while also reducing dependence on antimicrobials.

A recent scientific review published in Aquaculture International examines in depth the key elements that enable fish to develop their innate immune responses. According to the researchers, a central role in innate immunity is placed by retinoic acid-inducible gene I-like receptors (RLRs), a group of innate immune sensors that allow fish to detect infections – particularly viral infections – and trigger a rapid immune response.

A thorough understanding of the function of these receptors opens up new avenues for the development of more effective vaccines, capable of stimulating early immune responses more efficiently. In this context, retinoic acid-inducible gene receptors could be used as targets for the design of adjuvants that enhance vaccine efficacy without increasing the antigen load.

Research in this field also points to the potential of these receptors as a basis for more specific immunostimulants, aimed at activating particular innate immune pathways. This approach would enable progress towards more precise strategies, in contrast to the broad-spectrum products currently in use.

One of the study’s most interesting findings is the existence of genetic variations in these genes associated with different levels of disease resistance, reinforcing the relevance of these receptors in genetic selection programmes. Such programmes could help develop more resilient fish populations and reduce long-term health-related losses.

The researchers also highlight the relationship between the activation of these genes and environmental factors such as temperature and dissolved oxygen, providing further scientific support for integrating environmental management into disease prevention strategies in aquaculture.