Sand Shrimp

The work of a curious fellow
   
As with the swimming shrimp, I have had trouble classifying these walking shrimp. We find them on both sand and mud bottom. They look more like sand shrimp than anything else I have found.
Walking shrimp
Walking Shrimp
At first glance it appears one of the walking shrimp that came out of a hole in the mud picked up a small disk-like object with one of its feet. On closer inspection we think that the small disk-like object grabbed the leg of the shrimp. The shrimp sort of backs away shaking its leg.
Walking shrimp caught by something in mud
Walking shrimp caught by something in mud