I think I need a tough scavenger catfish for my 120 gallon. My pictus catfish has just been brutally mauled, and killed by "Lambchop" my Cobra Pike. I currently have a pair of Loisellei's in my tank, as well as the pike. I also have a Raphael catfish, who doesn't really do much, and a big featherfin synodontis, who is in a seperate tank for now. Is there any sort of bottomfeeder that would be able to stand up to such aggressive fish and do a good job cleaning up around the tank? I don't wan't anything enormous, because I am worried about overcrowding.