I have one and have for about 6 months. My favorite fish ever. Here is what I have learned about these guys.
They are social-they do best with a buddy.
Sexing-Females a lighter green with 9-11 "spines" males are darker with 11-13.
They can breathe out of water for about 4 or 5 hours.
THEY WILL ESCAPE if given the chance. ALL AREAS of top of tank must be sealed in some fashion.
They are NOT agressive. If you have small fish it will try and eat them as they rest on the bottom at night. However they are Poor hunters(its really funny to watch) they are almost blind. They hunt by smell alone so a fish will more than likely be too fast for it. Mine can catch juvenille guppies. They Love earth worms and Ghost shrimp.
They are very tolerant to a wide range of water conditions. Soft to hard acidic to alkaline.
They may attain lengths of 30-36 inches but will remain slender so a HUGE tank is not necessary. I have mine in a 90 and am confident that at full grown it will be fine in here. They love planted tanks.
I can not stress enough how important it is to make sure it cant get out. drop the water level an inch close all openings.
Oh they LOVE water bubbles. When I had mine in a non planted tank I had an airstone in that it would play for about 25% of the whole day. And its really enterating to watch them do this.
Bredding is possible but hard. They would probobly need a species tank... if you are interested I can send you some info on breeding if I still have it. I only have one but am going to get a male in the near future... hoping maybe they will give me kids as this by far my favorite fish out of all I have ever owned or seen in
FW tanks.
If I think of anything else I will let you know... or if you have any specific questions I can probobly help out as this is one fish I have done a lot of studying on to make sure it is happy.