Dave, only a week or two to get a permit, but the clearing agents are only interested in big consignments and most of them are not interested in live fish.
The problem is rather getting an agent to buy your fish and handle it from abroad, getting all the health certifcates required on your behalf from that side and getting all the export documentation in order and arrange the flights, transporting it to the airport and putting your fish on the plane. There are huge risks involved for them and for you and therefore it is not viable to import small quantities.