Help - Gourami Turning Aggressive

[sheree]

I've had a gold gourami for the past year with hardly any problems. She is about 4' and certainly the boss around the tank but until recently she has shown fairly no problems apart from hurting herself when I first got her which she pulled through. However, within the last fortnight or so, I've lost about 5 smaller fish such as otos and tetras. At first I put it down to just old age as they are all a few years old and there was no real sign of trauma. However, last night I caught the gourami in the act. She was zooming around the tank (180l) having a "mad half hour" and ran straight towards a head and tail light tetra, killing him outright. She also kept on knocking the thermometer against the glass loudly. I've seen her do this once or twice before but without any trouble until now and I'm now concerned about my other fish. She seems to have quietened down today but you can still see the other fish are quite tentative around her. I've checked all stats which are fine and i've always carried out weekly water changes of between 20-50%. Can anyone suggest why this is happening?

 

[Tokis-Phoenix]

How planted is this tank and can you describe what sort of planting you have ?

 

[sheree]

I have hydrophilia and vallis covering about 40% of the tank. There is 3 quite large monuments where the cories and loaches tend to hide out and unfortunately there isn't really much room for any more plants.

 

[Tokis-Phoenix]

Hmm the only two solutions i can offer you that i could see working are;

a. Get 2-4 more female gold gourami's- gold gourami's can handle each other a lot better than the tetras can with your current lone female, having some more gold gourami's will take your current females attention off the other fish in the tank and all she will be interested in is the other gold gourami's. This method works well for a lot of other typs of sociable fish with agressive/territorial tendancies like Tiger Barbs, Yoyo loaches, Seprae tetras etc and often works very well for many types of gourami's too .
If you do get anymore gourami's, it would be best to get some which are of similar or larger size than her, small new arivals may not change much about her behavior as they'll probably imediately end up in the bottom of the pecking order.

b. Simply rehome the female gold gourami- unless you can get her attentions off the other fish in the tank by getting some of her own kind to socialise with, then she will continue to pick on the other fish in the tank for as long as she feels like it (which could go on forever).


.


In the mean time, it may help re-arranging some of the planting in the tank- the planted area/s are her main territory, and if it is changed in appearance she will feel less sentimentally attached and territorial about it, also by changing the layout of the planting/decor in the tank, it will take her attentions off the other fish in the tank for a while as she explores the new layout.
For example when people have angelfish which have paired up for breeding and are vigorously defending their territory together and attacking any other fish that come near it, often the easiest way to stop the agression/territorialness from the angels is to re-arrange the decor and planting .