Dont keep them with anything under about 3 inches and keep an eye on them feeding as they are very fussy and can starve to death if not offered a food they will take. Remember they will hit at least 18 inches in length and can grow much larger (up to 30 inches) so a tank of at least 4x2x2' will be needed for an adult fish. They are also quite delicate so dont keep them with any aggressive fish and make sure that water quallity is pristine at all times as they are nitrate sensative.