75 gal is to small for a Senegal bichirs do. If you really wane add something I would keep it at a l-number. Then don't really stay in the same waterlevels and l-numbers can take a beating if necessary. Any other fish will probably get to big or there will be fights.I have actually been looking to get one i just have to get one of a decent size so he doesn't get eaten by my GT cause the only ones ive seen are like 1 inch long and that's about the same size as the worms he gets as treats.