WELL, my brother sold me his 55 gallon tank and everything that goes with it, including his fish, which he THOUGHT was a silver dollar. when he kept eating my other fish i started to research his kind and thought that he might be a pirahna. either way i wanted to get rid of him so i could have other fish so i took him to uncle bills and found out he is a red belly pacu and will continue to grow and grow and grow the rest of his 20 + years he may live. my tank will not accomodate him. hes only about 8 inches now and swims around head butting the glass like its not enough room. hes a beautiful fish and id love to keep him except i want other fish too. i put a plecostamus in with him last night and he was still alive when i left for work this morning... but sometimes he will let them live long enough to be confident before he inhales them.. even larger fish he will take bites out of. im not sure what i can put in with him. isnt he soposed to be a vegetarian???