FYNBOS FISH SPECIES
TWEE RIVER redfin
Red List status: Critically Endangered
The Twee River Redfin is closely related to the Clanwilliam redfin. Adults can live for up to six years. They reach an average size of 45mm in males and 42mm in females. They spawn between October and December and feed on benthic invertebrates, although adults also feed on insects floating on the water or on drift material.
Where you’ll find them
The Twee River redfin is restricted to the Twee River sub-catchment of the Doring River and its tributaries, including the Hex, Suurvlei and Middeldeur tributaries.
This species prefers deeper pools, particularly with overhanging vegetation and caves. Juveniles can often be found near Palmiet (Prionium serratum) or beneath overhanging vegetation.
A major threat to the Twee River redfin is Cape Kurper. The Cape Kurper is native to the Cape Fold Ecoregion, but NOT to the Twee River catchment. They were introduced in the 1980s by a farmer as a way of controlling mosquito populations. Now it competes with the Twee River redfin for resources. Cape Kurpers also likely catch juvenile redfins. Other non-native fish species include the Clanwilliam Yellowfish (Labeobarbus seeberi) – another fish species found in the Cape Fold Ecoregion, but not originally in the Twee River System. Rainbow Trout (Oncorhynchus mykiss) and Bluegill Sunfish (Leprmis macrochirus) were illegally stocked here in the 1990s. Other threats include habitat degradation due to intensive farming of fruit, as well as water abstraction during summer.
The Twee River System is a priority freshwater environment for fish conservation and is listed as a fish sanctuary in the National Freshwater Ecosystem Priority Areas project. But while some species are found in the Hexberg Nature Reserve, most are on land owned by private landowners. That’s why it’s vital to raise awareness of the conservation importance of this species with landowners here. Projects run by WWF South Africa have played a role in rehabilitating the catchment and improving agricultural practices. The Twee River redfin has been translocated to new sites at the Tuinskloof Dam – with good results. More projects have been proposed in this river system.
Sources: SANBI Red List of South African Species; Swimming on the Edge of Extinction (Garrow & Marr)
Help us protect these ancient species…
many of which are swimming on the edge of extinction.