1. Reason: Arowana's mouth is rotten, which may be due to bacterial infection, and they have strict requirements on water quality. If the water quality is too poor, they are easily infected with bacteria and cause their mouths to fester.

2. Treatment: Breeders need to isolate diseased fish immediately to prevent their bacteria from spreading to other fish. It is also necessary to raise the water temperature to 30 ℃ to promote their metabolism and speed up their recovery. If the mouth of Arowana is rotten seriously, the breeder needs to add some antibiotics in the water, such as penicillin and amoxicillin.

1. Reason: Arowana's mouth is rotten and may not be treated in time after trauma. Arowana has a fierce character and is prone to fighting. They all rely on their mouths to bite when fighting, so their mouths are easy to get hurt. In addition, Arowana preys quickly, and its mouth is prone to injury when preying. In addition, Arowana will also cause mouth injury when it hits the cylinder.

2. Treatment: The breeder needs to apply anti-inflammatory drugs to the injured arowana to avoid infection. They should also be changed regularly to avoid bacteria caused by poor water quality. It is also necessary to ensure that the water temperature and quality are stable, so as to prevent the wound from worsening. If the number of arowana raised is relatively large, the breeder should keep sufficient oxygen to avoid hypoxia.