White spot disease in penaeid shrimp is caused by white spot syndrome virus and causing serious threat to shrimp farming industry. The present study was carried out to determine the anti-viral activity of Turbinaria ornata against WSSV in freshwater carbs Paratelphusa hydrodromous. The crabs were injected with acetone extract of T. ornata along with WSSV and the experimental groups were observed for more than 60 days post-infection. The e cacy of the T. ornata acetone extract was con rmed by bioassay, histopathology, and in-silicoanalysis. The results of the present study con rmed that acetone extract of T. ornata has signi cant anti-viral activity against WSSV and it can be used as a possible prophylactic in shrimp culture for prevention of WSSV infection.