I put a peppermint shrimp and a cleaner shrimp in my tank about a week n a half ago. The peppermint is crawlin about and doin his job, but havent seen the other one since i put him in the tank. Is this normal or should i b concerned?

So... I only had 2 fish currently in my 10 gallon reef. A small 1 inch clownfish and an equally small 1 inch blackbar chromis. Both I've had for about a month and a half with no problems (other than that the blackbar likes to pick on my clown now and then, he's a bit of a bully). Weirdest thing...