If you want to have the ultimate predator tank with sharks and sting rays, then avoid using the standard sized aquariums and go for something that will maximize swimming space. Long, rectangular aquariums just won’t cut it. Sure, they provide plenty of room left to right, but their narrow footprint presents challenges when long sharks want to turn. The ideal shape tanks for these fish are large circular aquariums, or long tanks with rounded ends. These style aquariums allow sharks to swim constantly without having to make awkward turns, and they provide plenty of sandy areas for stingrays to burrow. Of course, we don’t recommend owning sharks or stingrays, as they are very sensitive and don’t often do well in captivity.