FYNBOS FISH SPECIES
Pseudobarbus sp. nov. heuningnes
Red List status: Endangered
This species is closely related to the Breede River redfin – as these rivers were all connected around 20,000 years ago. However, today these redfins have become speciated in the different river systems. More studies are required on the Heuningnes redfin, as little is known about its full range.
Where you’ll find them
They are known to occur in three sub-catchments of the Heuningnes River System: the Kars, Grashoek and Nuwejaars Rivers. The populations are completely isolated from each other – with non-native fish species inhabiting the stretches of water between them.
This Heuningnes redfin prefers murky water with high levels of dissolved salts. The beds of the pools where you’ll find the species, are mostly made up of sand, silt and mud. This is in contrast with many of the streams found in the Cape Fold Ecoregion, which are clear, with rocky substratum.
Bass species (Micropterus spp) are the biggest threat to the Heuningnes redfin. They’re found in the sections of the three rivers which are home to the redfin. A big challenge in this river system is the lack of natural barriers, to prevent the invasive fish from spreading. The upper Kars is home to the only viable population, given the presence of a bridge that has prevented the Spotted Bass (Micropterus punctulatus) from moving upstream.
Local initiatives are in place to protect the Nuwejaars River and wetlands, and its tributaries. The initiatives are currently focused on improving and rehabilitating the riparian zones (many have been overrun by invasive alien plants). As yet, there are no plans in the Nuwejaars River to remove the non-native fish, although a five-year drought has reduced these fish populations in sections of the river and in connected vleis. Conservation initiatives are also monitoring more closely the Heuningnes redfin in the Kars River. But more research is required to understand the distribution of the species, and conservation management actions are needed to protect the species.