Territory disputes? With both species only and community tanks, this can be a potential problem. It can be mitigated by overcrowding, i.e., having so many fish that no single fish can claim a territory. Even if your tank isn’t overcrowded, you can still sometimes ease such disputes if you move things around in the tank frequently (e.g., rocks, caves, decorations).
One of my 75g tanks is a Tanganyikan community tank (see photo above) with nine cichlids (five species). It contains the following (all adults) and is normally pretty docile:
- 2 x Neolamprologus leleupi
- 2 x Lamprologus tretocephalus
- 1 x Julidochromis marlieri
- 1 x Eretmodus cyanostictus
- 3 x Altolamprologus calvus
Things get a little dicey when the adult male Tret (5″) decides he wants a space to himself. Though the three Calvus equal him in size, they generally ignore him. However, he makes it known he’s not happy when any of them invade his space. Mistakingly, I left him too large an open area when I moved things around the other day. He promptly set up shop and wasted no time defending it. As typical of calvus and compressiceps species, they turn sideways to and curl their bodies so that their side scales are all that is exposed. This is their natural defense mechanism. The Tret will “peck” at them but otherwise doesn’t get extremely belligerent. They generally don’t back down, but the Tret doesn’t do any harm.
Because they (the Tret and the Calvus) were too frequently having these spats, I went ahead and re-arranged things. The Tret now has very little space he can claim that is easily defendable. As you can see from the photo above, the tank has numerous caves, nearly any of which he’ll happily occupy. However, none of them provide him a means to see anything other than what is in front of him, which amounts to very little open space. In fact, he’s most recently chosen the large ceramic cave on the right side of the tank, facing out (beside the piece of holey rock at the front). A close-up of his cave is below.
Sometimes it takes a little observation, a little patience, and a little understanding to figure out exactly what’s going on with your cichlids. I always say “Get to know your fish.” If you do that, you’ll know when something is going on, you’ll know the problem, and thus you’ll have a better idea of what to do about it.