territorial behaivior

[tgray]

I noticed in Instars picture gallery photos of more than one copperbanded butterfly per tank. I've seen a tank with 5 peaceful yellow tangs (100 gallon). Both of these tanks were not retailer tanks with a transient population. I realize each tank and fish is defferent but I would like to discover what makes it possible to do these (to me incredible) things? Superior condtions, food, chemistry, habitat etc. or merely putting a group in tank so aggresion is spread evenly or both. Or something else. Any ideas?
Thanks,Tim G

[schoeplein]

Yellow tangs school in the wild. If you have one that has established its territory, and you add one more - you'll still end up with one :-o. Add 3+ more at the same time and you're cool. Sometimes better off as tangs seem to be quite sociable. This is, however, not the case with angelfish as they do not school in the wild.

Same applies for butterfly fish - they school in the wild (not true for *all* butterflies). But to maintain your tank with several large specimens, you need quite the rockwork, swimspace and a conflaguration of filtering units.

[Richard]

Normally having a group of tangs will disperse aggression enough that no one fish will be injured. They will still spar with each other though. It is very much like keeping african cichlids where it is very difficult to keep only a few together because the dominant fish will kill the others but if you have a larger number of them things become peaceful, well relatively peaceful. With tangs there are exceptions and you could end up with one that becomes hyper dominant and will do it's best to kill off the others. In that case, the best solution is to get rid of the hyper dominant fish. Of course, to successfully keep a group of tangs you have to have sufficient space and excellent filtration to maintian high water quality.

Some things that help are to add them in groups. Adding them one at a time makes for a very rough introduction for the newcomer. Also if your planning a mixed group of tangs you'll want to add the more peaceful species first and let them get established before adding the more aggressive species such as Powder Blue's, Purple's etc.

Then keep your fingers crossed. There's a bit of luck involved too.

[blueboy]

i saw an interesting article in TFH last month about keeping pairs of tangs.