Disclosed is an assembly designed to encourage fish to enter a Coanda effect fish pumping system (10) to allow delousing through the pump. The process quickly decelerates the fish in a water tank (52) to their original speed of between 1.5 to 3 feet /second depending on pumping lift for a 10 inch diameter SILKSTREAMTMpump (10). As the fish guiding tube enters the tank (52), it is surrounded by a smooth diverging cone (24) slowing the water speed to the original fish speed. The fish are then guided by a tubular assembly (16) away from the water and lice into a second SILKSTREAMTM pump intake (18). The current changes within the SILKSTREAMTMCoanda effect pump (10, 12) provide delousing of the fish by orientating the fish in a forward direction as the fish pass through the pump.