DROPSY??

[Alligator head]

Is there any sign of dropsy?

 

[Rotaryp04s]

need better straight side body pics to confirm

 

[narayanang76]

It doesn't seem to be an issue from this pic, and may be tough to judge from the photos.

I have no first hand experience dealing with dropsy, though.

What filter setup in your 200 G tank?

Refer to the below thread from MFK itself, and search for keyword dropsy: https://www.monsterfishkeepers.com/forums/threads/arowana-disease-and-cure.16433/

Protruding Scales Disease(Dropsy)
Cause : Extreme sudden change in water temperature in the tank, sudden PH change , poor water conditions. Fatal disease. Symptoms : Scale tilt outwards and when making a turn a few scales will appear protruding out. When viewed from the top this becomes more obvious, the fish may stop eating and lose their sense of balance usually struggling to swim properly.If the scales continues to protrude till its near the head of the fish then it is in its final stage where within a few days it will die. Remedy :Raise water temperature to 34°C gradually (1 degree over 2 hour). Add 1% coarse salt to the water. Increase air supply to water. Do 25% water change every 2 days. Add tetracycline (yellow powder) as per the supplier written instruction. Add black water or Ketapam leaves to soften the water. Stop feeding for the time being. Continue treatment until the scales are flatten.