How to treat white spot disease in cultured grouper

Symptoms: White spot is one of the serious diseases of grouper, especially in high-density temporary culture ponds and cage culture. The disease spreads rapidly, and serious 3murs can kill all fish in the pond in 4 days, resulting in complications with paragonimus in cages, with an infection rate of 90% and a mortality rate of more than 50%. The disease is prevalent in Fujian, Guangdong and Zhejiang, and mostly occurs in summer. Pathogen: the pathogen is the grouper of ciliates. The body of the worm is small and slightly transparent, similar to that of freshwater carp, oval or oval in shape, with a size of 45 ~ 80 × 29 ~ 53 microns. There are 36 ciliated lines on the ventral side of the worm body, others are exposed, there is a round orifice in the middle of the front part, a large oval nucleus in the middle of the worm body, and a flower-shaped valvular body behind the large nucleus. Symptoms: the worm parasites on the body surface, gills and fins of grouper. There are irregular white spots on the body surface of diseased fish, and in severe cases, the white spots are linked together, and the fins of dead fish protrude forward and stick to the Gill cover, resulting in increased mucus on the body surface and Gill, slow flow, difficulty breathing and often floating on the surface. Diagnosis: the first diagnosis can be made according to the body surface symptoms. The diagnosis requires scraping mucus from the body surface and Gill for microscopic examination, and a large number of worms can be found.

Treatment: grouper white spot disease is a common disease in grouper cage culture, and its harm is also very serious, so the treatment of grouper white spot disease should be mastered. Specific methods are: (1) Copper sulfate sea water solution: soak the diseased fish in 2 mg / L copper sulfate seawater solution for 2 hours, then rinse with sea water and repeat every other day. (2) fresh water washing: put the diseased fish in fresh water for 4 minutes for 5 minutes, once a day for 3 consecutive days. (3) washing with bleach or potassium permanganate solution: put the diseased fish in 5mg / L bleach or potassium permanganate fresh water solution and rinse for 2 minutes, repeat every other day.