Red List of South African Species

Alternatively, Explore species
| National Red List categories | Partners |

Notes

For a long time, the Eastern Cape Redfin Pseudobarbus afer was considered to be the most widely distributed redfin species in the Cape Fold Ecoregion of South Africa, with a distribution range spanning across more than 28 isolated river systems from the Sundays near Port Elizabeth to the Klein Braak which discharges into Mossel Bay (Skelton, 1988). A genetic study by Swartz et al (2007, 2009) revealed four deeply divergent taxonomic units: (i) the Mandela lineage (restricted to the Baakens, Swartkops and Sundays), (ii) the St Francis lineage (confined to the Gamtoos and adjacent river systems), (iii) the Krom lineage (endemic to the Krom River system), and, (iv) the Forest lineage (widely distributed from the Tsitsikamma to the Klein Brak River system). Recently, Chakona and Skelton (2017) demonstrated that the Mandela, Krom and St Francis (Gamtoos) lineages can be separated based on scale counts, length of oral barbels and consistent differences in body colour pattern, supporting their status as distinct species. These authors described the St Francis lineage as a new species P. swartzi, resurrected P. senticeps (Smith, 1936) as a valid species (the Krom lineage), and re-described P. afer sensu stricto (Peters, 1864) (Mandela lineage). The Forest lineage is closely related to P. phlegethon from the Olifants River system on the west coast of South Africa, suggesting that it does not belong to P. afer sensu lato (Swartz et al. 2007, 2009; Chakona and Skelton 2017). The taxonomic status of the Forest lineage will be addressed in a further study that will incorporate the more closely related P. phlegethon. Here we assess Pseudobarbus swartzi.

habitat_narrative

Freshwater (=Inland waters)

Pseudobarbus swartzi occurs in pools and riffles in mountain streams with clear or peat stained water. The ecology and biology of the P. swartzi (previously included under the widespread Pseudobarbus afer sensu lato) was extensively studied by Cambray (1994) and Cambray and Hecht (1995). For a small-bodied fish species, P. swartzi grows fairly slowly, reaching a maximum age at 5-6 years and a length of 110 mm (Cambray and Hecht 1995). Maturity is reached at approximately 40 mm (2-3 years old) and P. swartzi have a protracted spawning season lasting from November to March (Cambray 1994). The unpredictable rainfall patterns and flow variability result in redfins adapting to optimise survival under these conditions. Females have a number of different egg sizes in their ovaries, which indicates serial spawning (where each female may spawn multiple times in a spawning season) allowing a number of opportunities to spawn, therefore increasing the chances of survival in such a dynamic environment (Cambray 1994). During spawning, P. swartzi move out of pool habitats into riffles and deposit non-adhesive eggs on the bottom of the stream in cobble habitat where the eggs fall into cracks and spaces between the cobbles (Cambray 1994). The eggs hatch after two days, and at this time the larvae are photophobic (avoid light) and rely on their yolk sac for nutrition. After about five days they exhibit positive phototaxis (light attraction) and swim out of the interstitial spaces and crevices between cobbles and enter the water column from where they disperse passively downstream (Cambray 1994). Feeding typically starts approximately 10 days after hatching. Pseudobarbus swartzi are omnivorous, feeding mainly from the stream bottom on algae and aquatic insects (Cambray 1994, Skelton 2001).

Not much information here?

SANBI is currently in the process of adding more information about species to this database.

Search for this species on The Encyclopedia of Life