Author(s): Rajeev Kumar Jha, Soy Daniel Wisoyo, Kristina and Sarayut Srisombat

Abstract: White spot syndrome virus (WSSV) has been listed as the most contagious pathogen causing severe mortality in farmed shrimp and substantial economic losses. A bioassay experiment was conducted to determine Cynodon dactylon extract's efficacy as an anti-WSSV treatment at the laboratory scale and cage level. A pond trial was performed to optimize and investigate the effects of C. dactylon-enriched feed. The trial's first step was performed using feed coated with 2% and 3% of ethanol-extracted C. dactylon. The shrimp were challenged with the virus on day 15 of feeding with the treatment feed and monitored. A total of 100% survival of shrimp was obtained in both treatment groups. The (Rajeev anti-viral) RAV-s C group had the best protection (100% survival) of three groups treated with crude extracts, including RAV-s A (10%), RAV-s B (15%) and RAV-s C (20%) mixed feed. Similar results were obtained in the cage level trial with crude extracts, where the RAV-s C group had the highest survival (100%) followed by RAV-s A (68%) and RAV-s B (85.05%). Pond trials were conducted in commercial ponds. A total of 20 units of shrimp ponds of the same size (5,000 m2) and location were selected for the trial. The treatment ponds' productivity was higher (12.7 ton/ha) than that of the control ponds (11.79 ton/ha). WSSV cases were not recorded in the control and treatment ponds. This study showed that C. dactylon extract has anti-WSSV properties and has no negative impact on shrimp growth.

DOI: 10.22271/fish.2020.v8.i6c.2388

Pages: 192-199  |  668 Views  175 Downloads

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