I set up a 36 gallon bow front over a year ago. Some of the first fish I stocked in the tank were 3 Bumblebee catfish (supposedly of the South American variety). Recently I've had some unexplained fish deaths. The smaller two Bumblebee catfish (each about two inches in length) and a handful of tetras (Columbian, Rosy, and Black Phantom) have died seemingly randomly over the past month or so. Today I got home to this scene (see picture): an injured rosy tetra dorsal fin nearly missing and circular damage around the area, and a black phantom tetra with his tail fin nearly missing and damage to his entire abdomen (if fish have those). So I think I'm pretty sure what (or who) the culprit of my fish angst is. I just pulled the last and biggest of the 3 Bumblebee cats out of the tank and put him in quarantine because it looks like he's been munching on the other fish. He'll be going back to my LFS tomorrow. He is about 3 inches long and very healthy (full grown for a SA, but I'm not so sure he's not an Asian given the aggresion). He was the only fish in the tank with a mouth big enough to do this kind of damage, and the damage is consistent with his mouth size. I thought I was fighting a fungal/bacterial problem, but I'm pretty sure this guy was just maiming the other fish when they would go dormant at night. If anyone else here has had experience with this sort of thing, ease let me know. There's still that little bit of hesitation that I could be wrong since all I've been able to observe is the aftermath of the attacks, and not the actual attacks.