Lettuce nuddibranch found in half

[Naiad]

What could have torn him in half? I only found the front half. He was still alive but died shortly after. I fear there is another hidden predator in the tank. The only inhabitants are 2 pipefish and 2 mandarins and common CUC.

 

[Wiz]

I had this happen too. I assumed it was my pump. :-(

 

[Naiad]

I normally have in the past but these pumps and power heads are all covered to protect the pipes. He has been stuck to the foam guard on the powerhead before but couldn't get sucked in. It makes me so sad to see him in such shape

 

[Naiad]

Could this be the culprit?