Actually I always heard that the only way to get them to retain their external gills is to keep them in a tank that has an extremely high amount of oxygen (since they are useless otherwise).keonetfish;4769405; said:If you keep poplypterus in oxygen depleted water, they will grow those gill things the axolotl or whatever that thing is has. I wouldn't recommend this, but it is natural for them to do this and they can also breath air directly.
Nighttouch;4767255; said:I'm a huge fan of polypterids. Senegalus or Delhezi would work well in a 55g. Also, african butterfly fish are a good "WTF" fish for those that have never seen them.