watchman goby

I've had a pistol shrimp in my tank for a while now. About 2 weeks ago I added a watchman goby. I released the watchman goby near (ish) the place the pistol shrimp calls home. Now I have the pistol shrimp in her original location under a large rock toward the left side of the tank and the...

I QT a watchman goby, added it to my DT, it was active and out and about for about a week then disappeared. I haven't seen her in about a month. When do I decide she died and got eaten by the shrimp? I did not get an ammonia spike that would indicate a dead body somewhere (and I do have a lid)...