Nothing to worry about... That's completely normal. Looks like it's healthy and doing quite well.
What you're seeing is that it's trying to lop off it's fingers to reproduce. I had one that was >10 in across that used to drop "fingers" monthly the same way. You'll see the white spots and then it will slowly separate the "finger" from the main body. You can easily help it along if you're up to it by cutting off the "finger". Either way, there's nothing that looks concerning.
If you're gonna frag it, you'll need to rubber band it to a frag rock. They don't glue well... There are a lot of videos on youtube on how best to frag a devils hand.
Hope that helps!
