endemism in the rivers of the olifants/doring basin is unusually high for south africa, with eight species endemic to the system. the upper olifants river is one of the main dwelling places of adult sawfins ("pseudobarbus serra"). this local endemic is classified as endangered by the iucn. at present it is so rare as to be jeopardized by angling or fishing and may not be killed or caught; a long-lived species, it needs several years to grow undisturbed but reaches an adult almost 40 cm after a decade. capenature has done trials to adapt it for aquaculture or fishery, but this requires better conservation of the river ecosystem. the clanwilliam redfin (""p." calidus") is another threatened and legally protected species found in the olifants river; it is more