Aggressive male kribensis behavior towards tank mates
Aggressive male kribensis behavior towards tank mates
I'm stumped, my male kribensis has suddenly turned on every fish in the tank, including his female partner. They've been paired up for about 2 months, showing all the usual spawning behaviour, but no fry yet. Lately, they were digging a lot and the female was hiding for a couple of days, then she reappeared and everything seemed fine. But a few days later, the male just started attacking her out of the blue. Even the Serpae Tetra, who never bother the kribs, are getting chased. I thought maybe adding a couple more females would distract him from the original female, so I got two more today. But now he's after them too. I'm upgrading to a 260 litre tank tomorrow, hoping the extra space will calm him down a bit.
Re: Aggressive male kribensis behavior towards tank mates
I'm going to take a guess that he's probably protecting some eggs or newly hatched fry, given the sudden change in behavior. Adding new fish, especially with cichlids, can actually make things worse when they're guarding their nest - it just adds to the stress and makes them more aggressive. It's like they're thinking, 'more intruders, time to get defensive'.
When you move to the bigger tank, try leaving the male and his original partner behind, and see if you can spot any babies. If you don't see any after a couple of weeks, you can carefully check under the rock or whatever he's hiding under to see what's going on.
Make sure to leave some plants and hiding places in the tank, so the parents feel more secure. You don't want to add to their stress levels.
Also, if you're planning to use the old filter in the new tank, consider leaving it on the old tank but taking half the filter material and putting it in the new filter. Then, top up both filters with new material.
For the first few weeks in the new tank, I'd recommend reducing the feeding and keeping a close eye on ammonia and nitrite levels. If you do get any readings above 0, do a 75% water change and give the substrate a good gravel clean.
When you move to the bigger tank, try leaving the male and his original partner behind, and see if you can spot any babies. If you don't see any after a couple of weeks, you can carefully check under the rock or whatever he's hiding under to see what's going on.
Make sure to leave some plants and hiding places in the tank, so the parents feel more secure. You don't want to add to their stress levels.
Also, if you're planning to use the old filter in the new tank, consider leaving it on the old tank but taking half the filter material and putting it in the new filter. Then, top up both filters with new material.
For the first few weeks in the new tank, I'd recommend reducing the feeding and keeping a close eye on ammonia and nitrite levels. If you do get any readings above 0, do a 75% water change and give the substrate a good gravel clean.
Re: Aggressive male kribensis behavior towards tank mates
I agree with coltin, the behaviour you're describing does sound like they're being territorial due to eggs or fry. The fact that they've been showing spawning behaviour and the female was hiding for a couple of days suggests that this could be the case.
In my experience, Kribs are best kept in pairs, one male and one female. Adding extra females is only going to cause more problems. Even in a larger tank, I'd stick to one pair. You might get away with two pairs in a very large tank, but it's not worth the risk.
Kribs can be quite territorial when spawning, but in a big enough tank, they can coexist with other fish without too much trouble. I'm guessing your current tank is on the smaller side, which is probably why you're having issues.
Upgrading to a bigger tank will give all your fish more space and should help reduce the aggression. I'd follow coltin's advice and keep the original pair in the current tank, and move the other fish to the new one. This will give you a chance to see if there are any eggs or fry, and then you can decide what to do next.
As for the two new female Kribs, I'd take them back to the shop. You're only asking for more problems by keeping them.
In my experience, Kribs are best kept in pairs, one male and one female. Adding extra females is only going to cause more problems. Even in a larger tank, I'd stick to one pair. You might get away with two pairs in a very large tank, but it's not worth the risk.
Kribs can be quite territorial when spawning, but in a big enough tank, they can coexist with other fish without too much trouble. I'm guessing your current tank is on the smaller side, which is probably why you're having issues.
Upgrading to a bigger tank will give all your fish more space and should help reduce the aggression. I'd follow coltin's advice and keep the original pair in the current tank, and move the other fish to the new one. This will give you a chance to see if there are any eggs or fry, and then you can decide what to do next.
As for the two new female Kribs, I'd take them back to the shop. You're only asking for more problems by keeping them.