Camels initially originated from the United States several thousand years ago before migrating north-west across modern-day Alaska and reaching China. They would have traveled close to the ocean, in which there's the possibility that a camel had seen a shark swim close by. Additionally, given the harsh climate of the time for camels to be migrating in the north, there's also the possibility that a camel could have died as the ocean was expanding. Therefore a shark could encounter the remains of a camel and know of its existence.
Or we could take a camel the ocean and introduce it to a shark. Not me though, I have a fear of sharks. Screw those creepy feckers they ain't eating me alive