Sawfin

The Sawfin is omnivorous, but mainly eats aquatic insects and their larvae.

The Sawfin (Barbus serra), also known as Clanwilliam Sawfin, is a ray-finned fish species in the family Cyprinidae. It is endemic to the Western Cape Province of South Africa, where it was formerly widespread in the Olifants River and its tributaries. Its range has decreased throughout most of the 20th century, and by now it is apparently only found in the upper Olifants River as well as the Biedou, Doring, Driehoeks, Jan Dissels, Oorlogskloof, Ratels and Tra Tra Rivers.

It is rather euryoecious, inhabiting a wide variety of small and large rivers. While young fish are common in pools in the foothills, adults will move further down to where the rivers enter the coastal plain and the water is deeper.

Long-Lived and Slow-Growing

Sawfins is long-lived and slow-growing, with yearlings being about 10 cm (3.9 in) long. It is only half-grown at about 4 years of age, and can get more than 10 years old. Its breeding season runs from late spring to summer (October to December), when schools of adults form to migrate upriver to shallow riffles with cobble ground, where they spawn.

Sawfin is considered Endangered by the IUCN, as it has declined much between the 1930s and 1970s. This seems to have been mainly due to the introduced Smallmouth Bass (Micropterus dolomieu), which can kill off antire subpopulations by eating the juveniles. Clanwilliam Yellowfish (Labeobarbus capensis) might be regarded as a competitor for food, but this is apparently not significant. Other threats are water pollution and overuse, mainly due to agriculture