When a fish lies with its back down, its abdomen up, or its side, it can't move normally for a long time, and it loses its ornamental value when it sinks to the bottom of the tank.

Etiology: The difference of water temperature changes is too large, and the fish is suddenly frightened and overeating, resulting in fat dysfunction.

Prevention and control methods: raise the water temperature, gradually increase the oxygen content in the water, keep the water clean, feed a small amount of live food in stages, and induce sick fish to eat. Tie the dorsal fin with fine nylon thread and press the foam board on the water surface to help the fish turn over and assist in treatment.