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Email the author (Login required) Effective control and treatment of Rhabdosynochus viridisi (Monogenea: Diplectanidae) in Centropomus viridis (Teleostei: Centropomidae) in marine aquaculture
Submited: 2024-09-27 12:36:36 | Published: 2025-06-30 18:48:32
DOI: https://doi.org/10.3856/vol53-issue3-fulltext-3338
Abstract
The prevalence of infection by the monogenean Rhabdosynochus viridisi in the Pacific white snook (Centropomus viridis) is a significant threat to the species' long-term viability in aquaculture. This study assessed the efficacy of five treatments: freshwater (FW), formalin (FOR), dermo-gard® AQUA (DG), praziquantel + fenbendazole + pyrantel pamoate (PZQ), and albendazole (ALB). Two experiments were conducted in vitro: 1) a detached-parasite assay, where individual adult parasites were exposed directly to chemical treatments, and 2) an attached-parasite assay, where tests were carried out with parasites on the gills of fish maintained under controlled conditions. In the first experiment, PZQ treatment resulted in 100% parasite mortality within 15 min of exposure. The DG, FOR, and ALB treatments exhibited promising results when administered 3 h after the initial exposure. The results of the attached parasite assay indicated that the ALB, DG, FOR and PZQ treatments dislodged and eventually killed 100% of the parasites on the gills after 1 h. In contrast, the PZQ and FW treatments did not dislodge parasites from the gills. Thus, when considering the efficacy of treatments under fish-farm conditions, it is essential to evaluate their effectiveness and implied economic cost when applied to farmed fish stocks.
