it is possible and i know some very skilled aquarist that have successfilly breed and raised the fry. the problem with breeding sw fish (for most fish anyway) is that the babies, start out and move through larvel stage whereas most fw hatch into small fish. In order to raise the larvel clowns u need to grow their food which is plankton, rotifers, and baby brine. This is time consuming and difficult, along with this they need to be raised in a safe enviorment so that the larvel clowns arent killed by fish or inverts or a conventional filter. I am aware of a book which has everything to do with clowns but am not aware of how well it discusses breeding.