Mississippi Department of Marine Resources agents say the shrimp in Mississippi Sound are still too small to open the 2009 season.
So Louisiana shrimp were being sold at Biloxi's commercial harbor.
Officials say they don't know when the Mississippi season will open.
A spokesperson said the Mississippi Sound water is warming up, which is helping shrimp grow faster.
Tuesday's sample netted 83 count shrimp. Until that total gets down to 68, Mississippi waters will remain closed.