I have a yellow watchman and pistol shrimp. I love watching them work together! If you get one, leave a bunch of shell fragments near the openings to The burrow and the shrimp will use them to shore up the walls inside the burrow. The shrimp can move pieces of shell as big as he is!! Mine has built an entire "hallway" leading up to the burrow opening out of shell frags to prevent sand from closin the opening. I've had to replenish the shell frag pile a few times over couple months. My goby doesn't leave the shrimps side, so he doesnt sand sift at all, which I kinda wanted him to. The only downside to the shrimp is that I know he killed a couple of cerith snails cuz I saw their shells shoring up walls near the entrance to he burrow.