Another cleaner shrimp molting ?

[bkolfo4]

My cleaner shrimp just disappeared Sunday morning. I have since seen two antennas floating around, but no shell.
I have had him for three weeks. Other fish in the tank: sixline wrasse, false perc clown, royal gramma, scooter blenny.
He has been eating good and very active in the tank.
My live rock has quite a few small places he could get that I would not be able to see him. . .
Do any of the fish I have sound like something that would want to eat a cleaner?
How fast can a cleanup crew of only 7 hermits eat up a shell?
How long do I wait before I assume he is dead?
I have been checking the water a couple of times a day waiting for Amonia to spike, but it looks good. . .
Thanks!
Brian

 

[angelsrock]

the only fish possible of attacking it would be the sixline but i doubt it. if you don't see it within a week start panicing.