White Spot Disease (WSD)

White Spot Disease is a highly contagious viral disease affecting crustaceans, especially shrimps/prawns, leading to mass mortality in aquaculture.
Causative Agent: White Spot Syndrome Virus (WSSV), a double-stranded DNA virus belonging to genus Whispovirus and family Nimaviridae.
Host Range: All decapod crustaceans including prawns, crabs and lobsters in marine, brackish and freshwater ecosystems.
Symptoms: Loss of appetite, lethargy, reddish body discoloration and distinct white circular spots on the carapace and exoskeleton.
Transmission: Occurs through both vertical and horizontal routes.
Vertical Transmission: From infected broodstock to post-larvae.
Horizontal Transmission: Through carrier organisms, contaminated water, or cannibalism of infected crustaceans.
Distribution: Reported in several Asian countries including India, China, Bangladesh, Myanmar,Thailand, Vietnam, Indonesia, Japan and Iran.
Impact: Causes mass mortality in shrimp culture and significant economic losses to aquaculture.