A review of thePseudobarbus afer(Peters, 1864) species complex (Teleostei, Cyprinidae) in the eastern Cape Fold Ecoregion of South Africa.
The Eastern Cape redfin,Pseudobarbus afer, has long been considered to be a single widespread and variable species occurring in multiple isolated river systems in the Cape Fold Ecoregion (CFE) at the southern tip of Africa. Mitochondrial cytochromeband control region sequence data of individuals from populations currently assigned toPseudobarbus aferacross the species' distribution range revealed existence of four deeply divergent taxonomic units: (i) the Mandela lineage confined to the Sundays, Swartkops and Baakens river systems, (ii) the Krom lineage endemic to the Krom River system, (iii) the St Francis lineage occurring in the Gamtoos and adjacent river systems, and (iv) the Forest lineage occurring in several coastal river systems from the Tsitsikamma to the Klein Brak River system. The Forest lineage is closely related toPseudobarbus phlegethonfrom the Olifants River system on the west coast of South Africa, suggesting that it does not belong toPseudobarbus afers.l. Herein we focus on the three lineages within thePseudobarbus afers.l. complex and provide new diagnosis forPseudobarbus afers.s (Mandela lineage), revalidatePseudobarbus senticeps(Krom lineage) as a distinct species, and describe a new speciesPseudobarbus swartzi(St Francis lineage). The three species exhibit subtle differences, which explains why they were previously considered to represent a single variable and widespread species.Pseudobarbus senticepsdiffers from bothPseudobarbus aferandPseudobarbus swartziby having fewer (i.e. larger) scales (25-33, mode 29 lateral line scale series; 10-12, mode 11 circumpeduncular scales) and presence of a lateral stripe which terminates in a conspicuous triangular blotch at the base of the caudal fin. Long barbels which reach or surpass the vertical through the posterior edge of the eye further separatePseudobarbus senticepsfromPseudobarbus afers.s. which possesses simple short barbels which do not reach the vertical through the posterior margin of the eye.Pseudobarbus afers.s differs fromPseudobarbus swartzisp. n.by possession of fewer scale rows along the lateral line (29-35, mode 32vs34-37, mode 36 inPseudobarbus swartzi), fewer scales around the caudal peduncle (12-16, mode 12vs13-17, mode 16 inPseudobarbus swartzi) and a distinct mesh or net-like pigmentation pattern on latero-ventral scales.
South African Institute for Aquatic Biodiversity, Private Bag 1015, Grahamstown 6140, South Africa.
Albert
A
Chakona
South African Institute for Aquatic Biodiversity, Private Bag 1015, Grahamstown 6140, South Africa.
Paul H
PH
Skelton
Cape Fold Ecoregion; Pseudobarbus senticeps; Pseudobarbus swartzi; endemic hotspot; single barbeled redfins