Predation

[cilyjr]

Found this. It doesn't look like flatworms. They don't really seem to move so I am unsure if this is a predator or if it is a little bit of flesh left over. I attributed the death to an alkalinity swing but now am unsure.
What do you all think?

 

[xxkenny90xx]

That doesn't look like flesh to me.. They don't move if you poke them?

 

[cilyjr]

I'm pretty sure we are looking at scavengers picking at the last little bit of flesh.