Female Krib killed all males in tank!??

I had a horrible experience with my kribensis late yesterday evening! I am looking for advice on what may have happened. I have had these Kribensis since May, some purchased in June, but they have been here a good few months. They have been living in a 40 G Long tank, well planted with tons of caves.

This seemed to work! I had one pair, 1 spare adult male and 3 immature albino kribs. Because the tank was large enough with all the hiding places, it seemed to be fine. This pair had attempted to spawn before, it did fail - I think the male didn't fertilize the eggs or someone ate them - but there was NO strange behavior during that spawn.

This time the female paired up with a different male. I assumed due to the failed breeding and that this male had grown to be bigger than the other one. They had been clearly in spawning mode, and we confirmed there were eggs inside one of the statues that had been turned on its side. They guarded this diligently for a day or two, and then stopped. I assumed the male had not fertilized the eggs, similar to the last failed attempt.

They seemed to be ok, but the male seemed to be a little aggressive to the female and the other fish. But no krib fry and no overly aggressive behavior that would have made me remove fish.

All was fine most of the day yesterday. My husband did do the water change, and he did say he may have bumped the statue but he did not move it or pick it up or anything like that. All we know is sometime after this water change (we were out the rest of the night) One of the fish must have gone crazy.

I found at around midnight before I went to sleep, every male kribensis dead. The big male, the smaller male, and 2 immature suspected male albino kribs. There were also a couple of mountain minnows torn to pieces too. The only survivors were the main female Kribensis and 1 young female albino. I immediately moved the albino female left alive to a smaller tank - I was so upset to find all the carnage, I was not losing her too and I could not tell what happened!

The Main Female Kribensis did have a large chunk out of her tail. But I am not seeing signs of aggression from her right now with the other minnows. She is going back to the statue where the eggs were, but I thought it had failed because they all stopped guarding it.

Does anyone have ANY idea what happened here? I know that Kribs can be aggressive when spawning, but this is insane. And other spawns none of the fish acted like this. I cannot tell if the main male killed everyone and then tried to kill the female and she killed him, or just if she did all the damage. I'm surprised to see her not being aggressive towards the minnows left if she was the one going crazy.

Any ideas would be great. I just don't want anything like that to happen again.

 

Oh my goodness!
I'm so sorry!

I don't keep Kribs so, really, I am no help.

Hopefully someone can shed some light on this for you.

 

I'm sorry I don't keep my kribs in pairs so I've never seen their breeding behavior, I just wanted to say sorry for all the trouble you had.

 

Wow I hope some one can help you. Isn't weird how the most docile pets can go crazy sometimes? I had rabbits do the same thing, all kill each other like that. Good luck!

 

That's really awful. Though it's good that one the two survived.
I have never kept kribensis but I know that if you bother a mother mouse they will freak and attack both their young and the male. Maybe krib are the same? It's possible she was suspicious, thinking the other fish had made an attempt to prey upon her eggs.

I hope you can get to the bottom of this!

 

HI my only thought is that with all the kribs in one that you could of had another pair form so that there was two pairs and maybe that cause the aggression

 

I have seen this behaviour in my kribs before, there could be multiple reasons. I am going to say I think the female has got fry or eggs, the mum and dad probably killed the other kribensis protecting the fry/eggs but the male might have eaten some and so the female had beaten him up and killed him and the reason she may have the chunk out of her tail is because kribensis fight back so one of the males would have taken that chunk out of her tail. She won't attack the other fish in the tank only chase them away. If you want, it is ok to have a look and move around the ornament to see if she has got fry or eggs. I have done it with mine before (lifting up plant pots to see how many eggs to see if she is laying more each time) Some will react differently though, mine just swam away a little bit then just came back though some may eat some of the fry in stress. But normally they just pick them up in their mouth. but if you feel unsure then you don't have to and can just wait to see if she brings out any fry within a week.

Ok that was a long explaination, not sure if I missed anything, ask any questions so that we can continue to help you.

 

I might add that every pair of kribensis will be different and the female may of not wanted the male to help raise the kids so she has chased him and beaten him, this is quite common.

 

sometimes, if the male is unwilling to spawn with her she will beat on him and this may occur in death of males if it looks savage she will probably have fry you will be fine to check
let us know how you get on so sorry for your losses