Hard to tell with the pics, but what squirtle is describing sounds like fish lymphocytosis. Try reading about it. Good luck with the gar.
Thanks for this, amount of times I have looked for a name!
I would not move the fish, I have had these bumps a few times mainly with red devils, but NEVER have I had 2 fish at the same time show bumps or any signs that it spreads. The other fish are most likely stronger.
For my jag as she was quite bad I used to do a massive water change every 2nd day and dump an awful lot of salts in the water after 2 weeks it popped and kept the water changes up for 1 more week. now she is pretty fine. Mind you some how she kept breeding the whole time.
regardless of what it is water changes and salt cant hurt