Ok my question is this; I have 2 55 gal aquariums and in 1 I have a red-tailed black shark, a albino rainbow shark, 2 upside down catfish species, not sure exactly which species they look like Syndotis nigriventris but they are darker and have a prominent leopard pattern all over unlike the broken pattern of nigriventris but bodyshape is identical and they really only swim upside down when in caves where they are almost always upside down moving or just resting, I also have two what I believe are Zamora cats they look identical to them with the black spot behind the gills and black outline on the dorsal, and anal fins and same body color the only thing is they dont have the characteristic shimmery spangles and bright spots on their sides? but getting back to the main question I also have seven half inch to 1 1/2in tiger barbs and was wondering if I could include some serpae tetras in this set up? I've had serpae's in with red tail sharks before but not the others especially the barbs whom they are similar to in the habit of being nippers if not in a descent number or school. I have not read or heard of these two species (tiger barbs and serpae being kept together) If u could help with the catfish questions I'd appreciate that too! I also would appreciate if you could suggest some other fish compatible with this setup.