Anyone have ideas on why my Red Head Tapajos have become aggressive towards each other when for more than a year they got along fine. I had 4 Red Head Tapajos and 2 Oscars in a 100 gallon (5 foot long) tank for over a year and everything was fine.
During a failed move of the tank I lost 2 of my Red Head Tapajos that jumped out of the container I was keeping them in during the move. Now the remaining 2 are always fighting with one another, when they never fought at all before. Fish are in the same tank, same decorations and they don't fight with the Oscars and the Oscars don't bother them. Any ideas?
AD Admin
This is typical behavior for most Geophagus species, they live in social groups in nature and will have a hierarchy within the group. So when you had 4 of them they were comfortable with their group size and had a group hierarchy in place.
Now with only a pair, you probably have a dominant male, which is larger and showing brighter orange/red coloration on the head, and a sub dominant showing little to no orange/red coloration and smaller in size. So basically just the big guy pushing the little guy around all day and no other Geo's to spread his interest, aggression, etc. between.
Best bet would be to pick up a couple of more Geo's and get them back into a more comfortable social group size and the aggression issues will dissipate.
You nailed it for sure one Red Tapajos Geo has grown much bigger than the other now and has the bright colors, while the other one is the same size and not much color.
When I can find more Red head Tapajos I will buy some more but they are usually much smaller than what mine have grown to, is that going to be a problem?
AD Admin
Actually smaller ones will work best with your existing Geo's as they will fall right in line to the larger dominant one already in the tank. As long as they are not small enough for the Oscars in your tank to bother you will be good.