He still has not shown back up. Should I be worrying at this point? he's been missing like 4 days now.Yeah shrimps hide after they molt. Think about it in the eyes of an emperor angelfish, there are two shrimps in front of you, one is freshly molted and soft skinned and tender, just the way he and all emperor angelfish prefer it, and the other one is tasty but hard and crunchy. Which one are you gonna choose? The tender one of course! So thats why they hide. Don't sweat about it, those things are like the cockroaches of the coral reef.