in my girlfriends 55 gallon tank it is dominated by some nice oscars, my bluegill bryan and pee wee the mean green sunfish. The catfish keep to themselves eating the blood worms and brime shrimp. Well now theres a new boss of the fish tank, the other oscars maybe be triple the size of him or even bigger but he will big the biggest in the end and the oscars may someday become food for him. today i got a red tail catfish and he wasted no time taking his area of the tank if any bait fish comes near him he eats it. And only being in the tank for about 20 minutes now his stomach is swollen like he ate a golf ball. i can already tell this is my new favorite fish. Any ideas for a name??? Heres some pics, sorry for the poor quality he doesnt like staying still.