Amazon Biotype

[FishyFriendisAWSM]

I have a 10 gallon aquarium that is based on the rio negro.  I have 3 neon tetras and 2 Julie corydoras catfish. I'm looking to add two more neon tetras and another type of tetra.  What other tetras are native to the rio negro? Thank you.

 

[fluttermoth]

I have to be honest; by the time you've got the fish you have already into proper sized groups (at least six, for both the neons and the cories), you won't have enough room for another species.

Really a 10g is too small for julies (although they'll actually be C. trilineatus).

 

[Wills]

Totally agree with Fluttermouth, sorry to say but the best bit about biotopes is to keep fish in really natural combinations and in low school numbers its not going to achieve that.
 
In small tanks like that you would be best off recreating an Ember Tetra or Green Neon Tetra biotope which would essentially be a large school of 1 species with correct planting and decor - leaf litter, tannin stained water etc. Or you could look at a smaller species of Dwarf Cichlid like one of the smaller Laetacaras, Nannacaras might work, Checkerboard Cichlids might work or one of the smaller Apisto species like Apistogramma Panduro and pair one of those species with the Ember or Green Neons in a smaller school. If you wanted to add in a second school and the full school of Cories your probably looking at closer to 30 gallons.
 
Sorry to be so negative
Wills

 

[TwoTankAmin]

Fish from the Rio Negro http/fish.mongabay.com/data/ecosystems/Rio%20Negro.htm
 

 

Fish Species in Rio Negro

Rises in E Colombia where it is known as the Guainía, flows E to the Venezuela boundary, forms a section of Colombia-Venezuela boundary, crosses Brazil and SE into Amazon river at Manaus; is joined to the Orinoco through the Casiquiare river



[No. of Species listed in Fishbase.org=206]

 

[FishyFriendisAWSM]

Thank you.  I chose to do neon tetras because they're my favorite.  I didn't know that a green neon tetra would be better.  I think I'll just stick to getting a few more neons.  by how many fish I wanted, the tank sounded pretty crowded.  Thank you once again.  Also, my cory's keep on swimming up and down the walls of my tank.  Why are they doing and what can I do to help it stop?

 

[Wills]

Green neons stay smaller which is why I suggested them
 
Is a bigger tank an option at all? Even a 20 gallon would be an improvement for these fish. And you could keep both groups in at least 5s or 6s and potentially get a dwarf cichlid in there. 
 
I think your cories are swimming up the sides as there may be a stronger current there they sometimes like to swim into flowing water. I've always thought it was just fun for them...
 
Wills

 

[FishyFriendisAWSM]

aren't cichlids aggressive 

oh also, I have plants to break the current up a little.  There's still a small current, its just very, very small. So I don't think its the current.

 

[Wills]

Cichlids often get a bad rep, they are more aggressive than tetras and cories etc but only in the sense they are sometimes territorial - South Americans are generally the most peaceful and the Dwarf Cichlids are the most peaceful still. For me its more intelligence rather than aggression in most cases.
 
Dwarf Cichlids always benefit from being in a community as well, being so small they often use the other fish in the area as an indication of how dangerous it is - with regards predators etc. So if there are no schooling fish it tells them there is a predator around and they need to hide and use their stress colouration to blend in where as with lots of schooling fish at all levels make them feel more confident and makes them want to show it! Thats how you get the best colour off it. Usually the problems are between the cichlids rather than the cichlids and other fish. Though with careful planning it can be avoided
 
Wills