AgCenter officials: keep an eye out for crawfish virus

Feb.23, 2008

Crawfish farmers need to keep an eye out for a deadly virus that was found in four south Louisiana ponds last year, LSU AgCenter biologists say.

There is no way to treat a pond infected with white spot syndrome virus, but making sure water quality is high can help crawfish fight off infection, Richard Johnson and researcher Ray McCain told producers Thursday.

"The only way to know whether you have low oxygen or not is with oxygen meters or kits," McClain said. "Many producers don't routinely check oxygen levels, but that is the only way to effectively manage your system."

They should also let boats dry completely before putting them from one pond into another, Johnson said.

The virus was confirmed last year in St. Martin, St. Landry and Vermilion parishes.

Johnson said the main symptoms are weakness and lethargy.

"If you think you have a problem, contact the LSU AgCenter," he said.

The disease affects crustaceans, including crawfish, crabs and lobsters; it does not affect humans. "But in Louisiana, the only species WSSV has been confirmed in is crawfish in freshwater ponds," Johnson said.

WSSV was first reported in farmed shrimp from Thailand and China in 1992-1993. It was later found in shrimp farms in south Texas and South Carolina.

A genetic test identifies the virus.