I picked up an Orange Spot Shrimp Goby and a Carribean Pistol Shrimp last week. I haven't seen the shrimp since I put it in the tank. It hit the water running. I see the goby hanging out under the same ledge all the time. But I don't see any sand flying or rubble piles that would suggest the shrimp is with the goby. Any Ideas on how to find out if the thing is still alive?