Hole in Serpent Starfish

[Python.Palette]

I received 2 Large serpent starfish yesterday. After drip acclimating them, I put them both in my tank. About two hours after getting them into the tank, one of them started to form a bubble in the top center. The bubble would inflate, and deflate. The bubble looked like it moved slightly. This morning when I woke up, there was a hole straight through the starfish. The starfish is still alive.

Any ideas about what happened/what is going on?

 

[AcroNem]

I had a purple one that got a hole just the same as that, I assume it was from trying to eat something too large. That was a couple weeks ago and is still moving around and trying to eat and the hole is starting to heal. If you notice it starts to disintegrate after not moving I'd remove it or put it in a QT.

 

[Reef keper]

Mine is doing that also, I think it may have been my pistol shrimp??!! There are lots of bubbles and they inflate and deflate fast. I think he got blasted by my candy cane pistol shrimp.