Fm With Oddballs?

[HODDY]

Hi,kust wondering meaning i don't have a clue about most oddballs.I was wondering if there is any oddballs that can be kept with a male firemouth in a 4ft tank(40g)

 

[Fate2006]

Sengal Bichir although not classified as an oddball (IMO) are nice, only grow to about a foot hmm not too sure what else...