I just bought my 3rd watchman goby he was around 2.5 inches acclimated him with no issues he swam openly ate frozen food right away. Since this morning no where to be found, I have had two in the same tank in the past and they go missing. My stocking is 2x Ocellaris clownfish, Vanderbuilt Chromis and a Exquisite Fairy Wrasse. I have never seen any of my fish be aggressive to any of the gobys in the past. I do have a Coral Banded Shrimp, which I could see eating my last two gobies as they were 1 inch or less, so I specifically went to LFS to get a bigger one. My coral banded shrimp is also not big at all I would say 1.5 inches body length he also hides in same spot in the rock work and only see him come out for pellets and other food that go near the cave. My wrasse also sleeps in the same cave during night and has no problems. I know Watchmans do hide, but in past ones I have owned that lived 6+ months would come out every other day to eat, before they would just be gone.