Problem with zebra fish: he is chasing all my fish around

Hey guys,

One week after I started my fish tanks, one of my two zebra fish (also the older one) started chasing my guppies and female black mollies. He seemed to chase the female mollies the most, and for the guppies, he liked to chase my orange male the most. It was only at food time, though, so we thought he was only fighting for food. But it turned out that it wasn't only that.

A few days later he started to chase them like there´s no tomorrow, but not only at food time. He was chasing our fish ALL the time!
We waited to see if he would stop, but sooner than you can imagine, he had bitten a piece out of my orange guppy´s tail. Since it was already night, I decided to go to sleep and give him back to the fish store the next day. As soon as I woke up at morning time, my female guppy´s tale also had a piece out. Then I Took the zebra fish back to the store, leaving only his little brother.

Now today, the little brother is also chasing the fish. Is this normal with zebra fish? Also, he seems to have no interest in bullying my Cardinal Tetra (I have only 1 left, for the others got ich and died). Why is he not chasing my Cardinal? Oh, and a female guppy of mine died yesterday, possibly the day that the little zebra fish started chasing the other fish. Is there a possibility that the zebra fish killed her? Please reply, this is urgent. I don't want to have no zebra fish in my tank, but I also don't want a fish that is harassing the others like he's the boss (because he's not, my male black molly is). So, what should I do? Is he suppost to be doing this or not? And is there any way to make him stop?

Here's a picture of the younger one:




And a picture of the orange guppy:





This is VERY urgent, please reply quickly.

 

zebra fish (zebra danio) should be in groups of at least 6. That will keep them all busy chasing each other like idiots instead of harassing your other tank mates. If you can not add more to make a school of them then you should remove the one you have

 

the zebra fish like to be in larger groups 5-8 or more. so they were probably stressed because they didn't have their group to disperse the energy.

EDIT: ah I was ninjaed

 

Okay, thanks for answering!

Okay, I'l see if I can remove him.

 

I also see in your profile that you don't know about the nitrogen cycle. Please read about it by clicking on the underlined words; it'll make your fish keeping experience much more enjoyable. Also, how big is your tank? Your problems could be partly because the fish don't have enough space to spread out.

 

My tank is a 10 gallon 40x30x30 centimeter tank.
Thanks for telling me about the cycle! I'l check it out right after posting this!

Thanks for answering!

 

The tank is likely cycling. The mollies definitely need a bigger tank. 20 gallons or so. Also considering danios like groups, you don't have space for more of them either. Can you considered a bigger tank or rehoming/returning some? I especially wouldn't cycle with so many fish.

Edit--id only keep those guppies. The way they reproduce you could have fifty by next week.

 

I'm not cycling-but sometimes in my tank a mini-cycle occurs! Ok, it´s decided! I´l return the danio by Saturday! I'l look to buying a bigger tank, but right now all I can do is to HOPE that the guppies don´t give birth (all my females are pregnant at stage 3 or 4)!

Thanks for answering!

 

If you don't do anything or have a heavily planted tank, the adult guppies will most likely snack on the guppy fry and keep them in check.

 

Guys, thank you all for the responses; my son, aged 9, was the one behind these posts. since I am working most of the time, he is taking (good) care of our small tank. and he's doing all the research and posting the questions. once again, would like to thank you all. Alexandre (my son) will post news soon. we will look into the nitrogen cycle as well.
kind regards
Marcus

Thanks, but until the guppies give birth, my tank will already be in a better condition. I also have a fry trap, so when we have fry, they will surely be safe.

Alex

 

Your son has very good grammar and spelling (better than my 9 year old brother). I'm so glad you are acting on what you have learned, and getting a bigger tank for your mollies.

 

Your son has very good grammar and spelling (better than my 9 year old brother). I'm so glad you are acting on what you have learned, and getting a bigger tank for your mollies.

Thanks so much! And thanks for the help too!

 

I know of a video which will help you both understand the nitrogen cycle.

Do you need one on how to clean your tank, as well?

 

I know of a video which will help you both understand the nitrogen cycle.

Do you need one on how to clean your tank, as well?

Thanks! How to clean my tank? Not really, but I'd really appreciate it!


Alex

 

OK, here!

And tell your mom I said you're pretty awesome. So polite!

 

OK, here!

And tell your mom I said you're pretty awesome. So polite!

OMG Thanks SO much! I'l watch the video right after posting this reply!