Ulcers on the surface body. The surface body of Liudun sawtail hanger showed ulcer wounds, with papular, red, swollen and hemorrhagic at the initial stage, and then violently damaged, festering, perforated, and gradually deepened and expanded.

It may be caused by injury during fishing and transportation, or chronic infection such as combined bacteria.

Fed with antibiotics or antibacterial agents, it seems Six shield sawtails infected with tuberculosis bacteria were isolated separately so as not to affect other fish.