Keeping Bns & Otos Together

[Inchworm]

Are BNs aggressive toward otos and/or other small fish?

I have a 55 gallon tank with tiny C. pygmaeus and C. habrosus and some little aspidoras. I originally had more than a dozen otos and had planned to get some little tetras too. I thought with a bunch of plants, this might be a nice change of pace since most of my fish are regular sized corydoras. Since I needed a place to grow out some baby BNs, and there was a lot of room here, I put about 15 in there. Now they are about 1 1/2" long.

Recently I noticed that the otos were no longer to be seen eating the zucchini and other vegetables I put in the tank, and one of them had what looked like a scrape on its head. I rounded them up and moved them to a different tank where they are happily sharing their zucchini with some much larger kuhli loaches.

I never observed any aggression toward the otos, but it does look like they are sturdy little fellows compared to the more delicate otos and might even tend to knock them around without intending harm.

Did I do the right thing, or was I worried for nothing?

 

[nmonks]

It all depends on the size of the tank. If you have a big tank with lots of green algae on delicate plant leaves, a school of Otocinclus might be fine, even if they lose out somewhat at feeding time when the Ancistrus shoo them away from the algae wafers. On the other hand, if the tank is small and most of the food the Otocinclus get will come from algae wafers given by the fishkeeper, then could easily starve over time.

Personally, because of their very specific needs, I consistently recommend against Otocinclus in community tanks. Yes, it can work, but the vast majority of specimens kept thus die within weeks, hence in terms of general advice, I tell people not to take the chance.

Cheers, Neale

 

[Inchworm]

Hi nmonks

Thanks for your reply. Fortunately, after losing a few within a short time after purchase, my original batch did well. The second batch that I added some time later has been doing well too. They are kept in a 55 gallon tank which is about as big as I can manage to keep in an apartment. They feed readily on zucchini, lettuce, kale and butternut squash and it provides the great bulk of their diet.

Picture taken 12-16-07:

The otos seem to do fine with either the dwarf or the full sized corys and my question was more about the BNs. While I did not observe these youngsters doing any aggressive behavior toward the otos, the otos seemed to have stopped eating their regular food and stayed on the sides of the tank.

Since the otos have been moved, the information is now just for my education. More important now is the question of whether or not the BNs might attack the dwarf corys. Is this something they are apt to do?

 

[nmonks]

I'm not experienced with dwarf cories as such, but I do keep the rather similar Aspidoras pauciradiatus, an inch-long Corydoras look-alike. My school seems to work just fine with a whiptail cat, but when I moved some peppered cories in there, the Aspidoras did become much more shy. So I'd tend to go with a "try it, but have a Plan B" response here.

Cheers, Neale