I had ray that ate 2 suction cups, one was green suction cup that you use to suction the thermometer to the tank. I don't know how it ate it, but when I got home it was gone and the thermometer was floating in the tank. I didn't think much of it actually, it acted normal and ate. Then about 4 months later, I was like what the hell is that? It was the suction cup it swallowed. I fished it out and it was hard as a rock.
The 2nd time it ate another one was about 2 months ago. This time it ate the larger clear one you use to suction the heater and things like that. Came home one day and noticed one of the suction cups missing. About 1 month ago I came home from weekend get away and noticed my ray acting funny... totally not normal and swimming with it front disk curl up and was not eating. Thinking what is going on? 2 days later I noticed the suction cup in the tank. Starting eating again.
That plastic clip might be hurting the fish though.