Agressive 6-line?


New member
I recently noticed my 6-line and one of my oscellaris clowns going at it. They are both around 2". The clown resides in my GBTA and is VERY territorial when any fish swims by. I guess my 6-line got fed up and started striking back. It's pretty sick! I didn't know 6-lines were agressive, but mine attacks like a snake.
Doesn't seem to be any harm done to either fish, the duels only last a few seconds.

Anybody else see this kind of behavior from their 6-lines?
Oh, yeah. My six line is only about 1 inch and it rules the tank. I've got 3 percula clowns, a blue tang, yellow tang, peppermint shrimp and a coral banded shrimp. I had a black sea horse too, but I think the wrasse popped him in the head one too many times.
They are generaly a very aggressive fish. I had all sorts of problems with mine. He attacked everything in sight. Nasty fish!
There's been alot of threads in this forum entitled "6-line from hell" ;)

Mine isn't too bad yet ... I've had him about 9 months, a bit aggressive when I add a new fish, but not to the point of hurting anyone. I love alot of the the flasher/fairy wrasses, but I can't have one as long as i have "Sixy" ... they will kill peaceful wrasses. He seems a little more tame in the 6ft tank, though (I used to have a 38g.)

He hasn't definned the clowns or anything?
<a href=showthread.php?s=&postid=6926821#post6926821 target=_blank>Originally posted</a> by tryffin

He hasn't definned the clowns or anything?

Not yet (crossing my fingers)!!
I've seen some pretty brutal six-lines. I don't think they're worth the aggressiveness, but that's just my opinion.

I have been warned about them from a friend who said he has had six lines kill his shrimp and crabs. I'm worried because I keep a six line and some peppermint shrimp together in a 20 gal that I use for cleaning pests off my rocks such as aptasia and flatworms.

Call me mad, but I would like to advice you to add more (!) sixlines tlo your tank. The problem of aggressiveness was long discussed in Germany, unless several people started adding groups of them to a tank and suddenly they became almost well-behaved.
If you have them in a group the dominant one will be a male and he will be busy chasing all the females in his harem. As soon as he is not able to keep all his females under control, the largest female will turn in to a male an try to start a new harem.
If you keep the sixline alone it will be just a little nasty fish, so please add more of them, although it seem counter-intuitive at the moment.
And please, also add another occelaris, pairs just have more fun.

Best wishes

More than one six-line? Could be. I loved mine for almost 2 years then it turned bad. I was glad when I found he had gone carpet surfing when I had the hood off due to no power due to a hurricane.

Anyone else tried more than one?
How many would you need? Would 3 be enough?
I can't get mine out and if a group would make mine happy, I might try that.
Hopefully it wouldn't become a triple nightmare :)
One of our LFS put two together in one of their small 10 gal holding tanks and they were fighting all the time by biting each others mouths.
Hmm... was thinking of getting a six-line, until I did a little research on RC.

I noticed them in the LPS and SPS tanks at most LFSs. They seemed to be a very nice little fish. Guess I was wrong!