Thanks JUICE!!
Mario,
The sixline is great with our other fish. At first he was sort of chased by the others, they kept running him off from all of their areas. Now he is used to everyone and they are used to him so he goes where he pleases in the tank and 99% of the time is not bothered by anyone else. He never bothers the other fish, but if they decide to run him off (very rarely now that they are used to him), he will stand his ground and let them to know to back off, and he is the second smallest fish in the tank, with the damsel being the smallest. I've never seen him initiate fights or chases with the other fish, but if they do to him, he lets them know quick to back off...then he goes on his merry little way looking for little critters to munch on. He has been no trouble at all.
What is odd, is that these the six-lines hide when they sleep, so we caught him under our zoa colony the other day. The area didn't even look big enough for him to get into, still don't know how he got there, but he was motionless under there. They say they do it for protection, they'll find a small spot and hide in it at night so as to avoid predators. They are awesome little fish!
Good night all!