If your looking for a shark you can keep in your home that resembles a real shark, take a look into smooth hound sharks aka dog fish. These sharks, as any shark, needs to be fed heavily and i would reccomend at least a 300 gal tank for an adult. They dont reach a very large size opposed to othe sharks out there, most likely reaching 2-3 feet in captivity. They are not aggresive but will eat small fish if housed together but should be fine housing with bull head sharks or cat shatks or sting rays. Be sure to offer any of these animals a varied diet. Your body cant get all its nutrition from one food source, same with any animal. Feed these animals chopped fish, squid, clams, mussels, shrimp, some will even dine on crabs or urchins if given the oppritunity.