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C. robinae biotope?

Posted: 30 Jan 2004, 18:41
by Gabriel
My first post! *waves*

Anyhow, I've got a 46-gallon Oceanic bowfront that I've set up as a Rio Negro biotope. Water temperature is about 79F, pH 6.5, hardness almost negligible. Filtration is a Fluval 404 with a resin sponge, Purigen, and peat granules (which account for the extreme softness). Furnishings include a large, "branchy" piece of bogwood that conveniently sheds a small amount of peaty-looking "dust" on the substrate, with smaller bits and sticks scattered around the tank; the substrate is a mix of fine sand and #3 gravel, both a very light beige. Plants include one Cabomba (probably carolinia, although I'd like to replace it with aquatica and/or furcata, if they're biotope-correct), some Limnobium laevigatum floating at the top, and a few Nymphaea lotus (which I know aren't biotope-correct, but I'll explain their inclusion below). The tank is lighted by 2x55W power compact bulbs.

I set this up as a cardinal tetra/Cory biotope, so the fish population currently includes 20 cardinal tetras, 6 Otos (again, recommended by Bleher, but I don't know if they're accurate), and 6 C. robinae. I've been tempted to get a few marthae hatchets, but I think smaller tanks look better with fewer species, so I've resisted (the fact that I can't find any helps, too).

So anyhow, I have few questions. First, do the furnishings and plants sound about right for a Rio Negro biotope? The reason I included tiger lotus--with misgivings-- was that Heiko Bleher included it in his recommendations for creating a Rio Negro biotope in the first issue of Nutrafin Aquatic News. I have no idea why he included a West African plant in a Brazilian biotope, but I thought the lotus might resemble a native plant that isn't available in the aquarium trade.

Second, does the fish population sound right? Originally I had included C. schwartzi, because Bleher recommended them, but when I looked them up on FishBase I found that they weren't listed as coming from the Negro. Maybe Purus is a tributary of the Rio Negro, but I wasn't sure. I saw here on Planet Catfish that robinae comes from the upper Rio Negro, as do the cardinal tetras, so I replaced the schwartzi with the robinae. Is this tank an accurate C. robinae biotope, to anyone's knowledge?

Finally, am I in danger of overstocking? I've never been comfortable with the notion that it's OK to cram as many fish into a system as can find room to swim, just as long as there's enough filtration. (Here again, Bleher and I part ways--he recommends almost 100 fish for a 40-gallon tank! I guess they occur in very high population densities in the wild.)

Sorry for the length of this post--I tend to get a little verbose. If you've managed to read all of this extremely long post, thanks for your patience, and for any advice you care to offer. :)

Posted: 31 Jan 2004, 09:58
by Yann
Hi!

Have you read there about
You can also read this

From what I know you might try another species that should fit better to what parameters you have, there are many other Rio Negro species that should adapt better to these parameters...

Cheers
Yann

Rio Negro cats

Posted: 31 Jan 2004, 19:53
by Gabriel
Thanks, Yann. I've wondered if that water might be too soft and acid for Corydoras, but the parameters I've seen for C. robinae at Fishbase list the pH from 6-8. Are there any species in particular that you'd suggest--ones that come from the same upper regions of the Rio Negro as cardinal tetras? Since the cardinals are the "stars" of the tank, the catfish would have to be small and non-predatory. Thanks! :)

Posted: 01 Feb 2004, 07:59
by Yann
Hi!

You could put fopr exemple , , or these is for the well known, you can also put some , , , or ...

Out of all these I would pick up between C. tukano, adolfoi, duplicareus and davidsandi, they should be the easiest of the group to find...

Cheers
Yann

Posted: 01 Feb 2004, 10:35
by hippyguy
I found this website today. Gives you all the corydoras species just from the rio negro.
http://personal.eunet.fi/pp/pak/cory.htm
Thought it might help :D

C. robinae biotope?

Posted: 01 Feb 2004, 18:12
by Gabriel
hippyguy, that's great. Thanks so much!

Yann, I'm going to take your advice and remove the robinae from my tank. I've been monitoring the water parameters over the past couple of days, and was startled to find that the pH actually averages much closer to 5.5 or even 5, rather than the mid-6 range I'd thought. No wonder my cardinals are doing so well.

Conversely, no wonder my poor Corys haven't been doing well. They're spooky and uninterested in eating. Since they aren't manifesting any other signs of distress like heavy breathing or hanging at the surface, I didn't think it was the pH. Obviously I was wrong. But the Otos don't seem fazed at all. They're doing great.

Do any of the species you listed, such as adolfoi, do well at very low pH, or is it not even worth the risk? I don't like to add chemicals to my tank on an almost daily basis, as I would in order to keep the pH above 5.5 or so, but at the same time my cardinals are doing so well with the very low pH. Maybe I should just forget about keeping Corys altogether? I'd hate to, but I don't want to keep returning fish--my LFS will kill me. :wink:

Posted: 08 Feb 2004, 17:45
by Yann
Hi!

Sorry for my late reply!

THe one that should do best in such water is , especially if you plan to breed them...
Cheers
Yannundefined