Danio Being a pain...

[sadielmorris]

Hi, I'm new to keeping tropical fish but I'm afraid I've caught the bug.

Currently in a Ten gallon aquarium I have the following:

1 black molly
3 Black skirt tetras
3 zebra danios

I'm not really sure if they are compatible but the guy at the petstore said they were and the tetras and the molly (and the other molly I had who passed away) all got along really well. I got the Zebra Danios about a week ago and one of them is a real jerk! He (or she) essentially paces the tank and chases and nips all the other fish into hiding, even the other danios. The only one he doesn't bother is the black molly.

Now I know that Danios and Tetras do better in groups of 6 but at this point I'd be overstocked with that many. The tank is well decorated with a peice of driftwood, some plastic plants and a ceramic inukshuk so there are plenty of hiding places for the harrassed. What I want to know is what I can do to improve the dynamics of the group. I don't think it's fair for this one fish to bully all the others into hiding. At one point I was going to flush him but my roomate convinced me I was crazy.

So what should I do about the bully?

Also the water is yellow from the driftwood, is there anything I can do about that apart from frequent partial water changes?

thanks for all your help I've learned so much just from reading the topics here.

 

[wendywc]

Like you said, the danios need to be in a bigger group which you don't have room for. But also, danios need more room to swim than a 10 gallon; a 20 gallon tank would be absolute minimum for a school of danios. These two major factors are probably the reason for the aggression you're seeing. Also, please don't flush any fish. You can always trade the danios at your LFS for store credit on supplies or something. Good luck.

 

[dwarfgourami]

Like Wendy says. Fish are bound by their instincts; there's no point in blaming a danio for not being fair. He can't step out of his instinct, and his instinct is telling him that he has to establish his position within the group hierarchy. That this is too much for his mates, since there are not enough rivals to spread his aggression or enough space for them to escape- well, he can't deal with that. He can't sit down and think 'ah, circumstances have changed, I must remodel my behaviour'. All he can do is carry on his instinctive behaviour, more and more obsessively because he is not getting the right answers.

Tbh I think danios get a raw deal. Because they are able to cope quite well with certain tank conditions (toxins), one tends to assume that they are "hardy fish" with no specific requirements of their own. In fact, they have very clearly defined needs (lots of space, big school), and when those needs are not met, will react with aggression.

Your black skirts are not reacting as violently, but it is very likely that they are also suffering from being in too small a group; they may start fin-nipping if they get stressed. I think the best thing would be a major reshuffle ( or a bigger tank).

Basically, a 10 gallon is only big enough for one species of schooling fish, and that has to be something small and with moderate activity needs (so not danios). They are quite tricky tanks to stock, but it can be done: there is a very good topic on the subject somewhere on this forum.

If you do decide to take the danios back- take them all. Just taking the bully out will mean that the next one in rank goes for top position- and he will only have one rival, who will get all the flak.

 

[ajbettle]

was it neseccerry to title with "danio being a dick" though?