musicman
Aquarium Advice Activist
When adding a new member to an established aquatic community, aggression and other territory issues are likely to occur. I understand that this is a normal part of the social dynamic when establishing the "pecking order."
I don't know much about aggression... and my recent experience has raised some questions. I hope this post can get an informative dialogue going, as not all fish-keepers will likely agree on what to do.
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Here's my story...
I have a moderately planted 10 gallon tank that has been housing two Gouramis for several months. The two Gourami's are an 4.5" Male Opal Gourami and a 3" Female Gold Gourami. The Female Gold Gourami used to be larger, and has a history of being rather aggressive, but over the past year has shrunk in size and appears to have mellowed in temperament. The Opal Gourami is clearly dominant among the two and the two coexisted for several months with plenty of chasing, but never any injury. The pair has never shown any inclination to breed.
With the introduction of the colder months, I needed a solution to keep my Bettas, who I had been keeping in bowls, warm enough. I decided to move one of my males into the tank with the Gouramis. He is large, for a Betta, but smaller than both of the Gourami's. Right before adding the Betta, I rearranged the interior of the tank.
At first, the Betta hid, coming out of his hiding place under the lava rock for only air and food. After a couple of days he became more active in the tank. The gold Gourami would chase him at first, and at one point took a bite out of his tail fin. Within short order, the Betta had turned the tables and would regularly chase the Gold one. The Opal had nothing to do with the Betta at this point.
After the Betta had asserted dominance over the Gold, he was soon chasing the Opal Gourami away. It didn't seem to matter that the Gourami was twice the size of the Betta. The Betta was clearly the king of the tank. He stopped messing with anyone and no-one messed with him. Several weeks passed without incident. During this time, the Gouramis didn't even chase each-other. Throughout this entire process, all three fish have maintained vibrant colors and have been eating normally.
Yesterday afternoon, I got back from class and noticed that the Betta had suffered injury. He had lost a scale near his dorsal fin and his tail fin now had a quarter inch split down the middle. He was surprisingly more active in the tank than I had ever seen him. If the Gouramis mess with him he quickly turns the tables by flaring is fins and gill flaps. He doesn't hesitate to make chase if he is bothered, but otherwise leaves the other two alone. He is spending about a fifth of his time in his hiding place.
***
I don't know what to do.
1. Should I remove the Betta or should I let this process run its course?
Also, other questions were raised...
2. How much aggression is normal?
3. How long does it take to establish territories and dominance?
4. Are minor injuries or fin damage an acceptable part of this process?
5. What factors play into the dominance of a particular fish?
I don't know much about aggression... and my recent experience has raised some questions. I hope this post can get an informative dialogue going, as not all fish-keepers will likely agree on what to do.
***
Here's my story...
I have a moderately planted 10 gallon tank that has been housing two Gouramis for several months. The two Gourami's are an 4.5" Male Opal Gourami and a 3" Female Gold Gourami. The Female Gold Gourami used to be larger, and has a history of being rather aggressive, but over the past year has shrunk in size and appears to have mellowed in temperament. The Opal Gourami is clearly dominant among the two and the two coexisted for several months with plenty of chasing, but never any injury. The pair has never shown any inclination to breed.
With the introduction of the colder months, I needed a solution to keep my Bettas, who I had been keeping in bowls, warm enough. I decided to move one of my males into the tank with the Gouramis. He is large, for a Betta, but smaller than both of the Gourami's. Right before adding the Betta, I rearranged the interior of the tank.
At first, the Betta hid, coming out of his hiding place under the lava rock for only air and food. After a couple of days he became more active in the tank. The gold Gourami would chase him at first, and at one point took a bite out of his tail fin. Within short order, the Betta had turned the tables and would regularly chase the Gold one. The Opal had nothing to do with the Betta at this point.
After the Betta had asserted dominance over the Gold, he was soon chasing the Opal Gourami away. It didn't seem to matter that the Gourami was twice the size of the Betta. The Betta was clearly the king of the tank. He stopped messing with anyone and no-one messed with him. Several weeks passed without incident. During this time, the Gouramis didn't even chase each-other. Throughout this entire process, all three fish have maintained vibrant colors and have been eating normally.
Yesterday afternoon, I got back from class and noticed that the Betta had suffered injury. He had lost a scale near his dorsal fin and his tail fin now had a quarter inch split down the middle. He was surprisingly more active in the tank than I had ever seen him. If the Gouramis mess with him he quickly turns the tables by flaring is fins and gill flaps. He doesn't hesitate to make chase if he is bothered, but otherwise leaves the other two alone. He is spending about a fifth of his time in his hiding place.
***
I don't know what to do.
1. Should I remove the Betta or should I let this process run its course?
Also, other questions were raised...
2. How much aggression is normal?
3. How long does it take to establish territories and dominance?
4. Are minor injuries or fin damage an acceptable part of this process?
5. What factors play into the dominance of a particular fish?
with a group of small peaceful schooling fish. The Gouramis are too large to keep in a 10 gal; as Siva said they are already suffering stunting which is very painful for the fish. Get a larger tank for the Gouramis and keep the Betta in the 10 with some other peaceful small tropical fish. Otherwise rehome Gouramis. Sorry. 
