Scientists working on African cyprinid fishes have raised the subgenus Clypeobarbus to generic rank and recognise seven species.
Clypeobarbus, which was first erected by Fowler in 1936, was previously considered to be a subgenus of the African Barbus genus.
However, a new study by Melanie Stiassny of the American Museum of Natural History and Kevin Conway of Saint Louis University has moved seven fish from this group to a genus of their own.
Conway and Stiassny, who published their findings in the latest issue of the journal Ichthyological Research, said that Clypeobarbus can be distinguished from African "Barbus" by the derived presence of a midlateral row of enlarged, shield-like scales with a dark near-vertical pigment streak just behind the rear of the gill cover.
They also possess a number of bone differences when compared to other "Barbus" species.
They have placed C. pleuropholis, C. congicus, C. pseudognathodon, C. bokomandi, C. hypsolepis, C. schoutedeni and C. bellcrossi in the genus.
They also redescribed C. bomokandi, a species from the Democratic Republic of Congo, which was previously known as Barbus bomokandi and was described by Myers in 1924.
These small barbs, which average around 4-5cm in length, are found mainly in the Congo River basin area, with C. bellcrossi being known only from the Upper Zambezi headwaters and C. hypsolepis being widespread through the Niger Delta, Upper Niger, Volta, Bandama and Agnebi basins.
The Barbus genus is in need of a thorough taxonomic overhaul. In 1996 Berrebi and co-authors proposed restricting the use of the Barbus name in the strictest sense (sensu stricto) to a group of 20 or so species from Europe, Southeast Asia and Northeast Africa.
Since then other 300 or so African species have been referred to as "Barbus", until their real taxonomic position is known.
For more information see the paper: Conway KW and MLJ Stiassny (2008) - Phylogenetic diagnosis of the African cyprinid genus Clypeobarbus (Ostariophysi: Cyprinidae), with the rehabilitation of Clypeobarbus bomokandi. Ichthyological Research (2008) 55: 260-266.