Agriculture
Disease

White Spot Disease in Black Tiger Shrimp
White Spot Disease or White Spot Syndrome Virus (WSSV) found in Black Tiger Shrimp is caused by Baculo virus. The disease was originally reported in China in 1993 , rapidly spread to many shrimp farming countries throughout Asia but was later contained. From 1999 until now, however, it hit Ecuadorian shrimp farms, severely affecting supply from the Western hemisphere. According to China's Xinhua news agency, Ecuador's export value this year decreased by 46% from the last year's level. Ecuador's Central Bank reported that its exports have dropped from 885 million US dollars in 1997 to less than 600 million US dollars in 1999.

Manifestation
Infected shrimps have red discoloration and white spots or patches about 0.5-2.0 mm in diameter on the inside surface of the carapaces. These white spots are abnormal deposits of calcium salts. White spot disease causes mass mortalities of shrimps that can reach 100% within 3-10 days after onset of these signs, especially juvenile shrimps of all ages and sizes.