Angelfish aggression

[orgetorix]

I have a problem regarding my angelfish. I added four yesterday and they have been harrassed constantly since. My tank is 300 gallons and pretty heavily planted. I have two koi angels about 3" tall, a darker angel about 3" tall, and two more of the same darker coloration about 6" tall (but with really tall fins, the body is about the same). The new additions are 2 striped and 2 golden angels that are easily 6" tall, body only. There has never been any aggression shown between these five angels. The four newcomers howver, have been cornered, with first the smaller of the dark angels nipping them and twitching around. Then the other two dark ones were doing the same thing. The two koi angls don't seem to care or notice. Finally, last night one of the new gold angels decided to fight back and began facing down the others, who backed off. This morning, howver, it is back to the same thing. Am I dealing with an aggressive pair/trio here or are they just establishing the pecking order? The tank seems big enough to house them all fine. The only other inhabitants aree some corys, plecos. sae, and a pair of gouramis who are always chaising each other. Thanks for your help.

[demon_surfer]

its because the angels that were already in the tank have established territories and a pecking order. The new additions have encroched on that.

This problem should eventually resolve itself, but if thats with the new angels just being at the bottom of the order or being stressed until death is something else.

My only suggestion on dealing with this yourself is to re arange the whole tank. move all the scenery around so all the territories are gone, that might help some.

or add a bunch more angels. The more there are the more the aggression will be spread out. with a 300 gallon you can have quite a few angels.

HTH

[orgetorix]

Thanks. Why are three of the five original angels being so dominant towards the newcomers while the other two don't seem to care? Also, is it common for fish twice the size to back down so easily or can I expect this to change once they get a bit more established?

[demon_surfer]

i cant comment on the issue with larger fish backing down. They are not exactly fighting, more testing each other so that probably has something to do with it.

the three fish you mentioned are probably the ones that are at the top of the established picking order while the other two are the victims.


or perhaps the two that are not fighting are the top ones who already have an established place so they are just letting the lower angels do the work of making sure that the new guys know their places.



As long as no real damage is being done there should be no problem. Think of it like sparing, they are testing each other.