Do fins grow back at all?

[Kryten]

My platy has most of the top of his back fin missing, which appears to have been removed by a mafia group of danios. They are gone now, but I want to know if this fin will grow back as it was before?

Do we know if this is causing the fish discomfort (i.e. have studies been done) as the fish doesn't swim around much at the moment except to catch food?

 

[Angel Lady]

that is probally the reason your platys are at the bottom of the tank did you put some melafix in with them thier fins grow back fast with this stuff I have had a betta that his fins were lunch for a couple of mollies I named these two mollies sadam and bin you wouldnt believe how mean these two really are thier are black mollies I had no ideal that they was so mean. but anyway the bettas fins grew back in a week with this stuff.

 

[DizzyDezzy]

Yep Melafix helps a lot - I had a neon with half his tail missing (bitten off by one of his buddy neons), and it grew back in about 4 days with melafix