What is White Spot Disease?

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What is White Spot Disease? Blog Image


Over the past month, white spot disease has affected over 100 acres of shrimp farming in Nagapattinam district, Tamil Nadu.

About White Spot Disease:

  • What is it? It is a highly contagious viral infection that affects crustaceans such as prawns, yabbies and crabs.
  • When found in high-intensity production areas, such as prawn farms, white spot disease results in the rapid mortality of prawns.
  • It has the potential to cause a significant financial impact on the farmed prawn industry.
  • Causative Agent:
    • White spot syndrome virus, a large DNA virus assigned as the only member of the genus Whispovirus (family Nimaviridae).
    • The virus is known to occur in fresh, brackish and marine water.
    • All life stages are potentially susceptible, from eggs to broodstock.
    • The virus does not pose a risk to food safety or human health.
  • When infected with White Spot Disease, the prawns may,
    • have loose shells;
    • show numerous white spots (0.5–2.0mm in diameter) on the inside surface of the shell;
    • be discoloured pink-to-red;
    • have unusual mortality;
    • come to the edge or water surface;
    • demonstrate unusual swimming patterns;
  • How it is spread:
    • It is primarily spread through the movement of infected animals or contaminated water.
    • Birds that feed on and move infected animals can spread the disease
    • Marine worms have been implicated as potential carriers of the disease.
  • Control:
    • Not moving crustaceans out of the white spot disease-restricted area.
    • Destruction, disposal and decontamination procedures for infected prawn premises.


Q1) What are crustaceans? 

Crustaceans are invertebrate animals in the phylum Arthropoda, subphylum Crustacea, and include the barnacle, crab, crayfish, lobster, shrimp, water flea, and pill bug. Although largely aquatic, a few crustaceans are found in terrestrial habitats. Of the nearly 40,000 aquatic species of crustaceans, only about 10% occur in freshwater habitats.

Source: 100 acres of shrimp farms hit by white spot disease in Nagapattinam, loss estimated in crores