It is possible to buy live saltwater sharks from wranglers at websites such as SharkSupply.com, but not all species are legal to possess due to conservation efforts, nor are all species suitable for life in captivity. As of 2015, it is legal to buy and own a limited number of saltwater shark species, including bonnetheads and lemon sharks. To own such sharks, they must be harvested legally, by a dealer who has a federal permit to capture and trade in sharks.
Shark fishing, capture, and ownership are all heavily regulated at both the state and federal level. For example, in Utah, it is illegal to collect, import, or possess a bull shark, while in Florida it is illegal to harvest many species, including whale sharks. In some cases, owners are also required to have permits. All hammerhead species are very tightly regulated by the federal government, and prospective owners need permits to possess them legally.
Although some species are not illegal to own, they are so difficult to transport and care for properly that ownership is prohibited by physical constraints. For example, Atlantic blacktips, spinner sharks, and silky sharks need much more space than is reasonable for private owners to provide.