Saprolegnia. There are floccules on the body of the Banyue Betta, which are a bit like cotton and moldy. Due to the increasing number of cotton-wool mycelium, the fish is overburdened, causing swimming disorder, loss of appetite, and becoming weaker and weaker, leading to death.

Treatment method: Malachite green can be used. You can also heat up yellow powder, salt or oxytetracycline. Salt has a good therapeutic effect. If the mycelium is very long, you can use tweezers to clip the mycelium, and then put it in low-concentration salt water to ensure the normal maintenance of the water quality.