Saprolegniasis

Overview

What is Saprolegniasis?

Saprolegniasis (also known as water mold disease, cotton mold disease, or winter disease) is a destructive infectious disease of freshwater fish and fish eggs caused by oomycetes of the genus Saprolegnia 18. The primary causative agents are Saprolegnia parasitica, S. diclina, and S. ferax, with S. parasitica widely regarded as the most virulent species in salmonid aquaculture 1 3. Although traditionally grouped with fungal diseases, Saprolegnia species are oomycetes belonging to the kingdom Stramenopila (Chromista) — they are evolutionarily distinct from true fungi, differing in cell wall composition (cellulose rather than chitin), a diploid life cycle, and the production of biflagellate zoospores 2.

Saprolegniasis affects a broad range of freshwater fish species, including Atlantic salmon (Salmo salar), rainbow trout (Oncorhynchus mykiss), brown trout (Salmo trutta), iridescent catfish (Pangasianodon hypophthalmus), and various ornamental fish, as well as salmonid eggs in hatcheries 6 3. The disease is globally distributed in freshwater aquaculture systems across Europe, North America, and Asia 18.

The economic significance of saprolegniasis increased sharply after the ban of malachite green in food fish production in the European Union (2002) and in most other countries during the early 2000s. Previously the cornerstone treatment, malachite green's removal from use prompted urgent search for alternative treatments and increased reliance on biosecurity measures 13 15. Annual losses attributable to saprolegniasis in global freshwater aquaculture are estimated in the tens of millions of dollars, with hatchery egg losses being particularly severe 16.

Clinical Signs of Saprolegniasis

Common Signs

• Physical Signs:

  • Cotton-like mycelial growth: The hallmark clinical sign is the appearance of white to grey, cotton-wool-like tufts of hyphae on the skin, fins, gills, and eggs of affected fish 2 6. These superficial mycelial colonies are visible to the naked eye and grow rapidly under favorable conditions.
  • Haemorrhagic ulcers: Beneath the mycelial mat, the underlying skin develops reddened, haemorrhagic ulcers exposing the dermis and, in advanced cases, underlying muscle tissue 5 7.
  • Fin erosion: Fin margins become ragged and necrotic at sites where mycelial colonization is established 6.
  • Egg infection: Saprolegnia is a major cause of egg mortality in salmonid hatcheries. Infected eggs develop a characteristic white mycelial halo; S. parasitica penetrates the intact chorion, while S. diclina destroys the chorion surface 3.

• Behavioural Changes:

  • Lethargy and isolation: Infected fish exhibit reduced activity and may separate from the school 6.
  • Flashing/rubbing: Fish rub against tank walls or substrates, likely in response to skin irritation caused by hyphal penetration 6 7.
  • Loss of appetite: Reduced feeding behaviour and progressive weight loss accompany active infection 18.

Progression of Clinical Signs

• Early Stages: Infection begins as small, discrete focal patches of whitish mycelium at sites of prior skin damage — wounds from handling, fin nips, or ectoparasite attachment provide primary entry points. Behavioural changes at this stage may be subtle 5 7.
• Advanced Stages: Mycelial colonies expand and coalesce; deep ulceration of the dermis and underlying muscle develops. In severe cases, hyphal invasion spreads to deeper tissues, causing osmoregulatory failure, systemic infection, and death 5 6.
• Impact on Fish Health: Saprolegniasis compromises the cutaneous barrier, leading to electrolyte imbalance and osmotic stress. The altered skin microbiome associated with infection — reduced bacterial diversity and increased opportunistic taxa such as Aeromonas — further predisposes fish to secondary infections 7. Mortality can be high in crowded hatchery and farm settings 18.

Causes of Saprolegniasis

Etiology

• Causative Agent: Saprolegnia parasitica is the primary pathogen in freshwater salmonid aquaculture. Phylogenetic analysis of the ITS region has identified at least five phylotypes of S. parasitica (S2–S6); phylotype S2 is overwhelmingly dominant in Scottish Atlantic salmon farms, accounting for 91.1% of all S. parasitica isolates recovered during epizootic periods 1. In Nova Scotia, both S1 and S2 strains co-circulate; S1 exhibits persistent zoospore motility and is consistently more virulent than S2 in experimental challenges, while S2 zoospores encyst and germinate more rapidly 4. Saprolegnia diclina clade IIIA is also frequently isolated from diseased eggs and employs a distinct infection strategy 3. Morphologically, S. parasitica produces non-septate branching hyphae, zoosporangia, secondary zoospores, encysted spores, and persistent vegetative gemmae; culture conditions significantly influence the formation of these structures 2.

• Transmission Methods:

  • Zoospore Dispersal: Saprolegnia reproduces asexually by releasing biflagellate primary zoospores from zoosporangia. These encyst, re-germinate as secondary zoospores, and ultimately encyst again before germinating into new hyphae. Zoospores are chemotactically attracted to fish skin exudates and damaged tissue 2 4.
  • Direct Contact: Infected fish and eggs release enormous numbers of zoospores into the water column, directly exposing neighboring healthy fish and eggs 5 3.
  • Environmental Reservoirs: Saprolegnia persists as saprotrophic mycelium on decaying organic matter — dead fish, uneaten feed, and feces — in tank substrates and biofilms, providing ongoing zoospore production even in the absence of visibly diseased hosts 18.

Risk Factors

• Environmental Factors: Saprolegnia parasitica shows temperature-sensitive growth, with optimal proliferation in the range of 12–24°C 6. Disease incidence is therefore highest during cold-water winter and early spring months in temperate regions. High organic load, poor water flow, and reduced dissolved oxygen further promote zoospore accumulation and infection 18.
• Host Factors: Pre-existing skin damage from handling, grading, net injuries, or ectoparasite attachment greatly increases susceptibility by providing infection entry points 5 7. Immunosuppression during spawning migration is a classical risk factor in wild fish 19. Notably, genetic resistance to S. parasitica exists among Atlantic salmon families, with heritability estimated at approximately 0.25, indicating meaningful potential for selective breeding 11.
• Farm Management Practices: High stocking densities increase contact rates and waterborne zoospore loads. Incomplete removal of dead eggs during incubation creates organic reservoirs for Saprolegnia growth and amplifies spore pressure on viable eggs 3 18.

Diagnosis

Diagnostic Methods

• Clinical Examination: The gross appearance of white cotton-like mycelial tufts on skin or eggs is highly characteristic of saprolegniasis and is sufficient for a presumptive field diagnosis 2 6. Inspection under a hand lens can confirm the filamentous oomycete growth.

• Laboratory Tests:

  • Microscopy: Wet-mount preparations of mycelial material reveal characteristic branching, non-septate hyphae and mature zoosporangia containing zoospores. Differentiation of Saprolegnia morphotypes based on gemma formation, zoosporangium shape, and zoospore release patterns allows species and strain-level characterization 2.
  • Culture Methods: Isolation on glucose-yeast extract agar or selective media supports pure culture growth for morphological and molecular characterization 5.
  • Molecular Methods (PCR/qPCR): Validated real-time qPCR assays targeting the ITS region enable specific, sensitive detection of S. parasitica in both fish mucus swabs and environmental water samples (eDNA), with 100% sensitivity for S. parasitica-positive water samples confirmed in field validation studies 8. Multiplex PCR protocols targeting both the rDNA-ITS region and a hypothetical protein gene allow species-level identification in a single reaction 9. Loop-mediated isothermal amplification (LAMP) offers superior analytical sensitivity compared to qPCR and is suitable for rapid, on-site diagnostics in as little as 20–60 minutes 10.
  • Histopathology: Tissue sections reveal hyphal invasion of the dermis and underlying musculature; PAS or Grocott staining highlights hyphal elements and confirms tissue penetration 7.

Differential Diagnosis

• Distinguishing Saprolegniasis from Other Conditions: Columnaris disease (Flavobacterium columnare) produces superficially similar white/yellow plaques on skin but is bacterial in origin and can be differentiated by Gram staining, culture, and PCR. True fungal infections (e.g., Ichthyophonus hoferi) cause internal granulomas rather than surface mycelium. Other oomycete genera (Aphanomyces, Pythium) require ITS sequencing or molecular methods to distinguish from Saprolegnia 2 8.

Treatment and Prevention

Treatment Options

• Current Treatments:

  • Chemical Treatments: Following the malachite green ban, approved treatments for saprolegniasis are limited. Formalin baths, hydrogen peroxide, bronopol (Pyceze®), and sodium chloride (salt) baths are used in various countries under national regulatory frameworks 18. Copper sulfate has demonstrated inhibitory activity against S. parasitica by disrupting protein synthesis, energy biogenesis, and carbohydrate metabolism 14.
  • Historical Treatments: Malachite green was used globally for decades as the gold-standard treatment against Saprolegnia on both fish and eggs. Its ban in food fish production (EU 2002; other countries by the early 2000s) due to carcinogenic and teratogenic properties created a significant therapeutic gap that persists today 15 13.
  • Treatment Challenges: Approved chemical alternatives are generally less efficacious than malachite green, and options vary considerably by jurisdiction. Limited approved therapeutants, environmental concerns over discharge, and the potential for tolerance development all complicate treatment programs 12 16.

• Emerging Treatments:

  • Boric acid: Inhibits Saprolegnia spore germination and mycelial growth in vitro, and effectively controls saprolegniasis in Atlantic salmon eyed eggs and yolk sac fry in vivo without adverse effects on hatchability or survival 13.
  • Linalool: A natural terpene alcohol found in various essential oils, linalool exerts dual activity — directly disrupting S. parasitica cell membranes and inhibiting protein synthesis, while simultaneously stimulating host complement and coagulation cascades, wound healing, and immune cell responses 17.
  • Plant extracts: Ethanolic extracts of pomegranate (Punica granatum) and thyme (Thymus vulgaris) significantly suppress mycelial growth of S. diclina at concentrations with low fish toxicity, representing promising natural alternatives to chemical fungicides 15.
  • Chlorhexidine: Identified by virtual screening against a cytochrome P450 fusion protein unique to Saprolegnia, chlorhexidine demonstrated strong anti-Saprolegnia activity in vitro (MIC₅₀ of 10.93 µg/ml), positioning it as a lead candidate for further in vivo development 16.
  • Clotrimazole: The imidazole antifungal arrested both spore and hyphal growth of S. parasitica isolated from catfish at a concentration of 2 mg/L, suggesting potential utility in non-salmonid aquaculture systems 6.

Preventive Measures

• Biosecurity Protocols:

  • Regular egg disinfection with approved products (hydrogen peroxide, bronopol) at recommended intervals throughout incubation 3 18.
  • Prompt and thorough removal of dead and moribund eggs from incubation trays to eliminate organic substrate for Saprolegnia growth 3.
  • Disinfection of equipment, nets, and footbaths for personnel to prevent cross-contamination between facilities 18.

• Farm Management Practices:

  • Minimizing handling-induced injuries through careful grading, crowding, and transfer procedures to reduce entry sites for Saprolegnia 18.
  • Maintaining optimal water quality: low organic load, adequate water flow, appropriate temperature, and sufficient dissolved oxygen to limit pathogen proliferation 6 18.
  • Incorporating Saprolegnia resistance into selective breeding programs; heritability estimates of ~0.25 in Atlantic salmon indicate meaningful scope for genetic improvement 11.

Case Studies

Real-World Examples

• Notable Outbreaks:

  • Scotland — Atlantic Salmon Hatcheries and Farms: A two-year surveillance study of 14 aquaculture sites in Scotland recovered 412 oomycete and fungal isolates from fish and water. Saprolegnia accounted for 66% of all oomycetes isolated, and S. parasitica phylotype S2 was overwhelmingly dominant — found at 12 of 14 sites, representing 91.1% of S. parasitica isolates during epizootic periods. The study demonstrated that water-column spore counts alone were insufficient to predict outbreak risk, highlighting the need for fish-derived sampling and molecular diagnostics 1.
  • India — Cage-Cultured Iridescent Catfish: Saprolegnia parasitica was isolated and characterized from cage-reared Pangasianodon hypophthalmus farmed in freshwater reservoirs in India. The pathogen displayed temperature-sensitive growth optimum of 12–24°C, consistent with heightened risk during cooler winter months. Clotrimazole was identified as an effective treatment candidate at 2 mg/L against both spore and hyphal stages 6.
  • Wild Salmonids — Ulcerative Dermal Necrosis (UDN): UDN produces severe ulcerative skin lesions in migrating wild Atlantic salmon and sea trout returning to rivers to spawn. Historically associated with Saprolegnia as a secondary colonizer of damaged skin, recent investigations confirm a complex, multifactorial etiology: the physiological transition from saltwater to freshwater triggers changes in skin physiology that increase susceptibility, with Saprolegnia acting as an opportunistic pathogen on compromised tissue 19.

• Lessons Learned: Effective management requires integrated approaches combining molecular surveillance of both water and fish, early removal of infected material, stress minimization, and timely application of approved treatments. Single-intervention strategies are insufficient for reliable control 1 18.

Data Insights

Disease Impact by Country

Scotland

• Saprolegniasis Incidence:

  • Saprolegniasis is among the most economically significant diseases affecting freshwater Atlantic salmon aquaculture in Scotland. A comprehensive two-year surveillance study across 14 farms demonstrated that Saprolegnia accounted for 66% of all oomycetes isolated 1.
  • Phylotype S2 of S. parasitica was the dominant strain at epizootic sites, detected at 12 of 14 sampling locations and representing 93.5% of fish-derived S. parasitica isolates and 91.1% of isolates recovered during outbreak periods 1.

• Diagnostic Insights:

  • Water sampling alone (spore counts) proved insufficient to predict outbreaks; S2 was isolated predominantly from fish rather than water samples, indicating that fish-derived diagnostics are essential for accurate surveillance and early warning 1.

• Treatment & Management:

  • Scottish farms rely primarily on approved chemical treatments (hydrogen peroxide, bronopol) following the malachite green ban, combined with strict egg disinfection protocols and dead egg removal during incubation 18.

Chile

• Saprolegniasis Incidence:

  • In Chile, saprolegniasis is not tracked as a standalone notifiable disease but is reported collectively under the category "Micosis" within the Programa Sanitario General de Manejo y Clasificación de Mortalidad (PSGM), the official mortality classification system operated by SERNAPESCA 20.
  • During 2025, mycosis was the leading infectious cause of mortality in freshwater Atlantic salmon, accounting for 60.2% of all infectious deaths — ahead of Flavobacteriosis (24.9%) 20. This represented an increase of +7.5 percentage points compared to 2024, the largest year-on-year increase recorded among infectious causes in that species 20.
  • In freshwater coho salmon, mycosis was the second infectious cause of mortality (34.4%), and showed the largest relative increase of any pathogen category: +18% compared to 2024, while IPN declined by 12.9% 20.
  • In rainbow trout, mycosis was a minor infectious cause (3.3%), with Flavobacteriosis dominant (95.1%) 20.

• Economic Impact:

  • The consistent increase in mycosis-attributed mortality across Atlantic salmon and coho salmon in 2025 indicates growing pressure from Saprolegniasis in Chilean freshwater hatcheries and grow-out facilities. Chile operates approximately 140 active freshwater centers annually, concentrated in Los Lagos (67), Araucanía (36), and Los Ríos (28) regions 20.

• Treatment & Management:

  • Chile does not have an approved specific treatment protocol for Saprolegniasis equivalent to those in Europe. Management relies on general biosecurity measures, water quality maintenance, and mortality reduction strategies within the PSGM framework. The upward trend in mycosis mortality in 2025 highlights the need for dedicated surveillance and treatment options in the Chilean freshwater sector 20.

India

• Saprolegniasis Incidence:

  • Saprolegnia parasitica has been confirmed as a significant pathogen of iridescent catfish (Pangasianodon hypophthalmus) in cage aquaculture systems in Indian freshwater reservoirs, representing a threat to one of South Asia's most economically important aquaculture species 6.

• Economic Impact:

  • The pathogen causes substantial mortality in catfish hatcheries and among juvenile fish, particularly during winter months when water temperatures fall within the pathogen's optimal growth range of 12–24°C 6.

• Treatment & Management:

  • In vitro sensitivity testing identified clotrimazole (MIC: 2 mg/L) as effective against both spore and hyphal stages, while commonly available compounds — boric acid, fluconazole, sodium thiosulfate, and potassium permanganate — showed negligible activity against S. parasitica isolates from this system 6.

Research and References

Latest Research Findings

Pathogenesis and Strain Biology

1. "Saprolegnia parasitica S1 and S2 Strains Differ in Zoospore Transition Timing and Pathogenicity Against Juvenile Atlantic Salmon (Salmo salar)" Authors: Duston, J., Sarowar, M. N., Schmidt-Schaun, T., & Astatkie, T. Reference: Journal of Fish Diseases, 2025. Key findings: S1 exhibited persistent zoospore motility and was consistently more virulent than S2 across challenge experiments through smolting season; susceptibility was independent of smolt status. DOI: 10.1111/jfd.70028

2. "Saprolegnia diclina IIIA and S. parasitica Employ Different Infection Strategies When Colonizing Eggs of Atlantic Salmon, Salmo salar L." Authors: Songe, M. M., Willems, A., Wiik-Nielsen, J., Thoen, E., Evensen, Ø., van West, P., & Skaar, I. Reference: Journal of Fish Diseases, 2015. Key findings: S. diclina destroys the egg chorion (necrotrophic strategy), while S. parasitica penetrates intact chorion (facultative biotrophic strategy) — two fundamentally different infection mechanisms in the same host. DOI: 10.1111/jfd.12368

Diagnostics and Surveillance

3. "Specific Phylotypes of Saprolegnia parasitica Associated with Atlantic Salmon Freshwater Aquaculture" Authors: Shreves, K. V., Saraiva, M., Ruba, T., Miller, C., Scott, E. M., McLaggan, D., & van West, P. Reference: Journal of Fungi, 2024; 10(1), 57. Key findings: A single phylotype (S2) dominates Saprolegnia epizootics in Scottish salmon farms; water-column spore counts alone are insufficient to predict outbreaks. DOI: 10.3390/jof10010057

4. "Detection and Quantification of the Oomycete Saprolegnia parasitica in Aquaculture Environments" Authors: Korkea-aho, T., Wiklund, T., Engblom, C., Vainikka, A., & Viljamaa-Dirks, S. Reference: Microorganisms, 2022; 10(11), 2186. Key findings: A validated real-time qPCR assay detected 100% of S. parasitica-positive water and mucus samples; suitable as both a diagnostic and environmental surveillance tool. DOI: 10.3390/microorganisms10112186

Alternative and Emerging Treatments

5. "Linalool Combats Saprolegnia parasitica Infections Through Direct Killing of Microbes and Modulation of Host Immune System" Authors: Tang, T., Zhong, W., Tang, P., Dai, R., Guo, J., Gao, Z., & Andayi, W. A. Reference: eLife, 2025; 14. Key findings: Linalool disrupts S. parasitica cell membranes and inhibits protein synthesis, while enhancing host complement, coagulation, wound healing, and beneficial gut microbiota — a multi-target natural alternative to chemical fungicides. DOI: 10.7554/eLife.100393

6. "Consensus Scoring-Guided Virtual Screening Identifies Potent Anti-Saprolegniasis Compounds Targeting a P450 Fusion Protein" Authors: Ali, M. A., Javaid, A., Muvva, C., Murugan, N. A., & Srivastava, V. Reference: Frontiers in Microbiology, 2026; 16, 1723326. Key findings: Chlorhexidine, identified by FDA-approved drug screening against a Saprolegnia-specific P450 protein, showed MIC₅₀ of 10.93 µg/ml in vitro — a promising candidate for therapeutic development. DOI: 10.3389/fmicb.2025.1723326

Genetics and Host Resistance

7. "Resistance to Saprolegnia parasitica Infection: A Heritable Trait in Atlantic Salmon" Authors: Misk, E., Gonen, S., & Garber, A. F. Reference: Journal of Fish Diseases, 2022. Key findings: Heritability of Saprolegnia resistance estimated at 0.25 across 105 pedigreed Atlantic salmon families; susceptible families showed a 1509% higher hazard of death compared to resistant families, confirming the potential of selective breeding to reduce saprolegniasis impact. DOI: 10.1111/jfd.13664

Conclusion

Saprolegniasis remains one of the most economically damaging infectious diseases in freshwater aquaculture worldwide, affecting salmonids, catfish, ornamental fish, and eggs. The withdrawal of malachite green from use in food fish production has left a persistent therapeutic gap: current approved alternatives — hydrogen peroxide, bronopol, formalin, and salt baths — provide partial control but are generally less effective, and the number of fully approved products varies substantially across jurisdictions 18.

Effective management of saprolegniasis in modern aquaculture requires integrated strategies: rigorous biosecurity including regular egg disinfection, prompt removal of dead organic material, and minimization of handling stress; molecular surveillance tools capable of detecting and quantifying S. parasitica at the strain level in both fish and water 8 1; and exploitation of the heritable component of resistance in Atlantic salmon breeding programs 11. Novel therapeutant candidates — linalool, chlorhexidine, boric acid, and plant-derived extracts — offer promising leads, but require robust in vivo validation and regulatory approval before widespread aquaculture use.

Future research priorities include: in vivo validation of emerging therapeutants across multiple host species; further characterization of Saprolegnia phylotype diversity and its relationship to virulence and geographic distribution; development of point-of-care molecular diagnostics for on-farm use; elucidation of host immune responses to guide immunostimulant strategies; and streamlined regulatory pathways to accelerate translation of research into farm practice.

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Last Modified: 2026-04-11

Tags: #Saprolegniasis, #Saprolegnia, #Oomycete, #ParasiticDiseases, #WaterMold, #Chile

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Citations:

[1] Shreves, K. V., Saraiva, M., Ruba, T., Miller, C., Scott, E. M., McLaggan, D., & van West, P. (2024). Specific phylotypes of Saprolegnia parasitica associated with Atlantic salmon freshwater aquaculture. Journal of Fungi, 10(1), 57. https://doi.org/10.3390/jof10010057 · Full text

[2] Erdei, N., Hardy, T., Verebélyi, V., Weiperth, A., Baska, F., & Eszterbauer, E. (2023). New insights into the morphological diversity of Saprolegnia parasitica (Oomycota) strains under in vitro culture conditions. Journal of Fungi, 9(10), 982. https://doi.org/10.3390/jof9100982 · Full text

[3] Songe, M. M., Willems, A., Wiik-Nielsen, J., Thoen, E., Evensen, Ø., van West, P., & Skaar, I. (2015). Saprolegnia diclina IIIA and S. parasitica employ different infection strategies when colonizing eggs of Atlantic salmon, Salmo salar L. Journal of Fish Diseases. https://doi.org/10.1111/jfd.12368 · Full text

[4] Duston, J., Sarowar, M. N., Schmidt-Schaun, T., & Astatkie, T. (2025). Saprolegnia parasitica S1 and S2 strains differ in zoospore transition timing and pathogenicity against juvenile Atlantic salmon (Salmo salar). Journal of Fish Diseases. https://doi.org/10.1111/jfd.70028 · Full text

[5] Songe, M. M., Thoen, E., Evensen, Ø., & Skaar, I. (2014). In vitro passages impact on virulence of Saprolegnia parasitica to Atlantic salmon, Salmo salar L. parr. Journal of Fish Diseases. https://doi.org/10.1111/jfd.12175 · Full text

[6] Rathod, S. K., Das, B. K., Tandel, R. S., Chatterjee, S., Das, N., Tripathi, G., Kumar, S., Panda, S. K., Patil, P. K., & Manna, S. K. (2024). Isolation and characterization of Saprolegnia parasitica from cage-reared Pangasianodon hypophthalmus and its sensitivity to different antifungal compounds. Scientific Reports, 14, 30829. https://doi.org/10.1038/s41598-024-80075-0 · Full text

[7] Pavić, D., Geček, S., Miljanović, A., Grbin, D., & Bielen, A. (2024). Characterization of bacterial communities on trout skin and eggs in relation to Saprolegnia parasitica infection status. Microorganisms, 12(8), 1733. https://doi.org/10.3390/microorganisms12081733 · Full text

[8] Korkea-aho, T., Wiklund, T., Engblom, C., Vainikka, A., & Viljamaa-Dirks, S. (2022). Detection and quantification of the oomycete Saprolegnia parasitica in aquaculture environments. Microorganisms, 10(11), 2186. https://doi.org/10.3390/microorganisms10112186 · Full text

[9] Chanu, K. V., Thakuria, D., Pant, V., Bisht, S., & Tandel, R. S. (2022). Development of multiplex PCR assay for species-specific detection and identification of Saprolegnia parasitica. Biotechnology Reports, 35, e00758. https://doi.org/10.1016/j.btre.2022.e00758 · Full text

[10] Ghosh, S., Straus, D. L., Good, C., & Phuntumart, V. (2021). Development and comparison of loop-mediated isothermal amplification with quantitative PCR for the specific detection of Saprolegnia spp. PLoS ONE, 16(12), e0250808. https://doi.org/10.1371/journal.pone.0250808 · Full text

[11] Misk, E., Gonen, S., & Garber, A. F. (2022). Resistance to Saprolegnia parasitica infection: A heritable trait in Atlantic salmon. Journal of Fish Diseases. https://doi.org/10.1111/jfd.13664 · Full text

[12] Tedesco, P., Fioravanti, M. L., & Galuppi, R. (2018). In vitro activity of chemicals and commercial products against Saprolegnia parasitica and Saprolegnia delica strains. Journal of Fish Diseases. https://doi.org/10.1111/jfd.12923 · Full text

[13] Ali, S. E., Thoen, E., Evensen, Ø., & Skaar, I. (2014). Boric acid inhibits germination and colonization of Saprolegnia spores in vitro and in vivo. PLoS ONE, 9(3), e91878. https://doi.org/10.1371/journal.pone.0091878 · Full text

[14] Hu, K., Ma, R.-R., Cheng, J.-M., Ye, X., Sun, Q., Yuan, H.-L., Liang, N., Fang, W.-H., Li, H.-R., & Yang, X.-L. (2016). Analysis of Saprolegnia parasitica transcriptome following treatment with copper sulfate. PLoS ONE, 11(2), e0147445. https://doi.org/10.1371/journal.pone.0147445 · Full text

[15] Mostafa, A. A., Al-Askar, A. A., & Yassin, M. T. (2020). Anti-saprolegnia potency of some plant extracts against Saprolegnia diclina, the causative agent of saprolegniasis. Saudi Journal of Biological Sciences, 27(7), 1924–1930. https://doi.org/10.1016/j.sjbs.2020.04.008 · Full text

[16] Ali, M. A., Javaid, A., Muvva, C., Murugan, N. A., & Srivastava, V. (2026). Consensus scoring-guided virtual screening identifies potent anti-saprolegniasis compounds targeting a P450 fusion protein. Frontiers in Microbiology, 16, 1723326. https://doi.org/10.3389/fmicb.2025.1723326 · Full text

[17] Tang, T., Zhong, W., Tang, P., Dai, R., Guo, J., Gao, Z., & Andayi, W. A. (2025). Linalool combats Saprolegnia parasitica infections through direct killing of microbes and modulation of host immune system. eLife, 14. https://doi.org/10.7554/eLife.100393 · Full text

[18] Buchmann, K. (2022). Control of parasitic diseases in aquaculture. Parasitology, 150(1), 1–18. https://doi.org/10.1017/S0031182022001093 · Full text

[19] Matras, M., Stachnik, M., Kycko, A., Wasiak, M., Paździor, E., Maj-Paluch, J., Borzym, E., & Reichert, M. (2024). Etiology of ulcerative dermal necrosis (UDN) in brown trout (Salmo trutta Morpha trutta) — Preliminary results. Pathogens, 13(3), 251. https://doi.org/10.3390/pathogens13030251 · Full text

[20] SERNAPESCA. (2025). Informe con antecedentes sanitarios de agua dulce y mar, año 2025. Servicio Nacional de Pesca y Acuicultura, Subdirección de Acuicultura, Departamento de Salud Animal. https://www.sernapesca.cl

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