Mysterious crayfish plague reported island-wide
February 26, 2014, 12:45 am TWN
TAIPEI--Taiwan has reported to the World Organization for Animal Health (OIE) information on a redclaw crayfish plague after massive die-offs of the crustaceans in several counties.
The Bureau of Animal and Plant Health Inspection and Quarantine said it notified the OIE Feb. 18 of the outbreak.
The bureau said that in Taiwan, redclaw crayfish were kept in the past as decorative aquarium additions and were not included in inspection and quarantine lists. With the latest plague, however, the bureau has decided to revise the regulations to include the crayfish.
The species was previously only allowed to be imported for research purposes and has never been approved for import or export, according to the Fisheries Agency.
Despite this, the bureau noted that people in four counties — Miaoli, Changhua, Pingtung and Yunlin — have been discovered raising redclaw crayfish illegally. Five ponds in Miaoli, Changhua and Pingtung were found to be infected with the plague in January, with a 40-percent mortality rate, representing 224,000 individual shellfish.
The bureau was later able to confirm the plague and notified the OIE.
Chao Pan-hua, deputy director-general of the bureau, said all the dead redclaw crayfish were destroyed Jan. 28 and that there is no question of any of them having made their way to market.
According to Cheng Shih-chin of Fish World Magazine, the species was introduced about two decades ago as a decorative aquarium addition, but did not prove very popular.
Over the past three or four years, however, people have turned to redclaw crayfish as an alternative to giant river prawns after the latter were found to be prone to disease ago.
Pond-raised redclaw crayfish sell for up to NT$400 (US$13) per catty (600 grams), compared with white shrimp, which sell for between NT$180 and NT$200 and giant tiger prawns at NT$300.