A new weapon has emerged in the fight against harmful parasites in gilthead seabream aquaculture! A recent study led by scientists from the University of Sassari (Italy), the University of Valencia (Spain), the University of Bologna (Italy), and Veronesi Holding S.p.A. (Italy) reported the effectiveness of three medications administered through fish feed against a particularly problematic parasite, Sparicotyle chrysophrii, which infects the gills of gilthead seabream (Sparus aurata). This parasite is a significant concern for fish farmers and causes considerable damage to these commercially important fish.
The Problem of Parasitism
Sparicotyle chrysophrii is a parasite that attaches to the gills of fish, disrupting their vital oxygen absorption function. This can lead to stunted growth, respiratory difficulty, and even death. Finding an effective treatment for this parasite is crucial for maintaining healthy fish populations in aquaculture.
Praziquantel, Emamectin Benzoate, and Fenbendazole
Researchers are exploring alternative and more sustainable solutions, and dietary treatments with antiparasitic drugs are promising.
- Praziquantel (PZQ): This drug has shown efficacy against similar parasites in other fish species. However, studies on gilthead seabream have faced challenges: fish find medicated feed unpalatable, leading to reduced drug intake and limited effectiveness.
- Fenbendazole (FBZ): This option is promising. Recent studies suggest that dietary FBZ could be effective against S. chrysophrii in gilthead seabream. Additionally, FBZ may offer a preventive or repellent effect against the parasite, further increasing its potential.
- Emamectin Benzoate (EMB): This drug, commonly used in salmon aquaculture, has been used off-label for S. chrysophrii treatment in gilthead seabream. However, its efficacy against monogenean parasites like S. chrysophrii is unclear.
Key Findings
The researchers studied three possible treatments administered through the fish’s diet: praziquantel (PZQ), emamectin benzoate (EMB), and fenbendazole (FBZ). The fish were infected with the parasite and then fed medicated feeds on alternate weeks over a four-week period.
Unfortunately, PZQ proved unpalatable for the fish, making it difficult to assess its effectiveness. EMB, on the other hand, although readily consumed, had negative side effects on the fish’s gills and showed no impact on the parasite.
However, the results for fenbendazole were promising! Fish treated with FBZ completely eliminated the parasite infestation. This suggests not only a curative effect but also a possible preventive or repellent action against S. chrysophrii.
What Does This Mean for the Future of Gilthead Seabream Aquaculture?
The potential of fenbendazole as a dietary treatment offers a significant advantage. It simplifies administration, reduces fish stress, and avoids environmental concerns associated with bath treatments. In summary, the main benefits for the gilthead seabream aquaculture industry include:
- Improved worker safety: Dietary treatments eliminate risks associated with handling formalin baths.
- Reduced environmental impact: Eliminating formalin use minimizes potential environmental contamination.
- Better fish welfare: Dietary treatments are less stressful for fish compared to bath treatments.
- Sustainable parasite control: Effective alternatives to formalin can contribute to a more sustainable aquaculture industry.
The study results pave the way for healthier gilthead seabream populations and a more sustainable aquaculture industry. By controlling Sparicotyle chrysophrii, fish farmers can improve the welfare of their stocks and ensure a consistent supply of gilthead seabream for consumers.
Conclusion
This research is an important step forward in managing sparicotylosis, a parasitic disease that can devastate gilthead seabream farms. Fenbendazole administered through medicated feed offers a potentially safe and effective solution for fish farmers.
Here are some key conclusions from this study:
- Praziquantel was not a viable option due to palatability issues.
- Emamectin benzoate, although consumed by the fish, had negative side effects and no effect on the parasite.
- Fenbendazole showed 100% efficacy in eliminating S. chrysophrii from gilthead seabream.
- Fenbendazole may also have a preventive or repellent effect against this parasite.
More research is needed to fully understand the long-term effects and optimal use of fenbendazole in aquaculture. However, this study offers new promising possibilities for controlling a major parasite affecting the gilthead seabream industry.
Contact
Paolo Merella
Department of Veterinary Medicine University of Sassari
Via Vienna 2 07100 Sassari Italy
Email: paolomerella@uniss.it
Reference (open access)
Merella, P., Montero, F. E., Parma, L., Morsiani, L., Cerri, R., Biase, A. D., Polinas, M., Murgia, C., Antuofermo, E., & Garippa, G. (2024). In Vivo Challenge Trials with Dietary Antiparasitics Reveal New Insights into the Practical Use of Fenbendazole against Sparicotyle chrysophrii (Monogenea) Infection in Sparus aurata (Teleostei). Aquaculture Research, 2024(1), 5515748. https://doi.org/10.1155/2024/5515748
