Scallop ...... gone !

So, I have 4 scallops that have been on a piece of LR I got from a friend, and that rock has been in my tank since December. Of the 4, there is only one that is not facing "down" and I can really see when it's open. It was fine right before I went to bed 6 hours ago, I just woke up and checked the tank and it was open WAAAYY more than I am used to, so I took a flashlight and shined at it .... cleaned up ! gone ! Just the "muscle" part is left, there is also some kind of skin on the inside of the shell and in there were 2 or 3 things, they looked like copecods but pretty big (5-7mm long ?) as soon as I shined the light in there they ran away really fast (they were light grayish in color) ....
Should I remove the scallop ? The green "fiber" foot part is still dark green on the inside of the shell but on the outside it's light green. I wonder how they could have cleaned it up so quickly !!!!

 

It died. It happens often with these smaller types of scallops. You can leave it in there. Your cleanup crew is already hard at work taking care of it. Eventually, it will just be another part of your live rock.