Symptoms and Control Methods of Brooklynella Disease in Lionfish

Pathogen: This parasite belongs to the genus Scyphidia (family Scyphidiidae, order Sessilida) found in grouper. In side view, the dorsal side is convex and the ventral side is flat; in ventral view, the body is oval or egg-shaped, measuring 45-80 x 29-53 um. The anterior ventral surface has a circular cytostome that can extend and retract. Cilia are present on the anterior part of the body and the anterior edge of the dorsal side. Behind the macronucleus there is a petal-like structure resembling a flower. This parasite reproduces by division.

Epidemiology: The disease is prevalent in hot weather and mainly affects fry measuring 20-50 mm. Water temperature above 25 degrees C. It is more commonly seen in high-density flow-through aquaculture and cage culture, with rapid onset and very high infection and mortality rates.

Symptoms: It mainly parasitizes the gills of fry. With heavy infestation, the gills turn grayish-white and are covered with many debris. Irregular white patches occasionally form on the body surface where the parasite attaches. The pectoral fins extend vertically outward from the sides of the body. Diseased fish often float at the water surface and swim sluggishly. Diagnosis can be confirmed by microscopic examination.

Control methods: 1. Soak fish in freshwater + 20 ppm furazolidone for 2-5 minutes. 2. Bathe fish in seawater + 200 ppm formalin for 20 minutes with aeration. 3. Bathe fish in seawater + 2 ppm copper sulfate for 10-20 minutes (use with caution for small fish).