Freshwater prawn, Macrobrachium rosenbergii has been viewed as an important species in shrimp farming industry due to its elevated economic value. Though regarded as moderately disease, Resistant species when compared to penaeid shrimp, You will find it is intended to be also under serious threat to a virus borne disease termed white tail disease wtd . The typical gross signs of wtd in infected pl are lethargy and opaque abdominal muscles. Mortality reached 100% within Two to three a few days following the first appearance of prawns with whitish muscles. The causative agents of this disease are m. Rosenbergii nodavirus mrnv and extra small virus xsv . Research result shows that mrnv plays a key role in wtd and that xsv is a satellite virus dependent on mrnv