Exophialiasis

Exophiala salmonis is a dematiaceous fungus recognized as a primary pathogen responsible for exophialiasis, a systemic mycotic infection. While predominantly an issue in salmonid fish farming, its presence in aquatic environments poses challenges for integrated aquaculture and hydroponic systems that rely on reused or recycled water sources.

The fungus is known for its ability to persist in water, sediments, and biofilm layers within technical equipment. In an agricultural and aquacultural context, it acts as a silent threat, potentially colonizing system components and affecting the health of aquatic organisms housed within the same facility as plant cultivation units.

Clinical signs of infection are characterized by the formation of granulomatous lesions throughout the visceral organs, including the kidneys and swim bladder. Affected organisms typically exhibit weight loss, lethargy, and localized skin discoloration. Persistent infection often leads to chronic debilitation of the affected population.

Environmental conditions that favor the proliferation of Exophiala salmonis include poor water quality, elevated organic matter levels, and inadequate maintenance of filtration units. The fungus spreads effectively through contaminated water flow and improperly sanitized equipment, making it a persistent resident in high-density production environments.

Prevention focuses on rigorous sanitation and the implementation of robust water treatment protocols. This includes the use of ultraviolet (UV) sterilization, ozone treatment, and regular mechanical cleaning of pipes and sumps. Maintaining optimal environmental parameters and reducing stress factors for the organisms are critical to preventing outbreaks and systemic fungal establishment.