Tropical Fish Forum

Tropical Fish Keeping Help and Advice => New Fishkeepers => Topic started by: Narm1971 on March 16, 2013, 11:59:05 AM

Title: Aggressive danio
Post by: Narm1971 on March 16, 2013, 11:59:05 AM

We started a 63l tank (my first aquarium) in January with 3 harlequins and 3 zebra danios. After 4 weeks we added a betta and 2 bronze corys.

The 2 biggest danios harassed the smaller one constantly until it got ill and died. We then noticed the bigger danio chasing the remaining one quite a bit. We then found the smaller danio dead last night. Now the remaining danio is bothering the harlequins. Have put it it in a smaller isolation net in the tank. I don't really want to risk the harlequins and other peaceful inhabitants. Should I ditch the danio? Views or advice welcome.

Thanks

Title: Re: Aggressive danio
Post by: Sue on March 16, 2013, 12:50:00 PM

Personally, I would exchange the remaining danios for more harlequins. Both are shoaling fish and need a minimum of six, with more being better. And danios, depsite their size, really need a bigger tank. They are such fast swimmers that they are more suited to a four foot tank.
When shoaling fish are kept in insufficient numbers, the alpha fish has only a few others to pick on. With larger numbers, the aggression (which is quite normal) is spread out amongst more fish so not one individual gets too much.

You also need more cories. Bronzes do get quite big, so maybe get 2 or 3 more rather than four (though that would be better). The dwarf cory species (pygmaeus, habrosus and hastatus) are more suited to smaller tanks. I have 7 pygmaeus in my 50 litre.

Title: Re: Aggressive danio
Post by: Narm1971 on March 21, 2013, 01:23:22 PM

Thanks for the advice.

I have arranged to rehome the danio at the weekend and will then look to build up the harlequin and cory stocks as you suggest.

 :)