I put in a 3 strip damsel in my tank last week and I have lost 2 fish from when I have put it in and both had no tales and one of my cardinal fish has lost some of it tale would this be the 3 strip damsel. I have 1 clown 2 cardinals and 2 chromis should I get the damsel out and take it back to the shop . The shop said it will be ok ??