Does anyone know of a South American fresh water stingray species that can stay in a 55 gallon fish tank for a few years before I would need a bigger tank. I love the freshwater rays, I've had some experience since I work at a small business aquarium store. And I attempted a Motoro stingray, but found out they get too big, and their growth is quicker than I thought so I returned him back. And I know the males stay smaller than the females. So I'll obviously be getting a male Ray because of size. I basically know all the care requirements just looking for the smallest species out there. I'll be getting a 200 gallon in about two years once I graduate high school this year and I get into college.