Rationale
(Changed due to Taxonomy|New Information|Knowledge of criteria)
The Marico Barb (Barbus motebensis) occurs in small streams and has a restricted distribution range with an extent of occurrence (EOO) of 12,552 km2 and very small area of occupancy (AOO) of 132 km2. It is known from approximately 20 locations, most of which are threatened by water abstraction associated with agriculture, with some also affected by urban water pollution. Other streams are impacted by seepage from mines via the dolomitic groundwater flow and also by competition from invasive alien fish. These impacts have been exacerbated by the severe recent droughts. The species qualifies as Near Threatened under criterion B1b(ii,iii,iv)+2b(ii,iii,iv).
Distribution
The species is limited to the upper catchments of the Marico, Elands and Crocodile (West) Rivers in North-West and Gauteng Provinces, South Africa.
There is currently little known about the population of this species.
Threats
Water abstraction, pollution and general habitat degradation through urbanization, agriculture and by seepage from mines via the dolomitic groundwater pose threats in the majority of tributaries of the Crocodile (West) Catchment, excluding the Magalies and Skeerpoort rivers which are still relatively unaltered. Crocodile (West) tributaries draining the Magaliesberg mountains are largely unaffected in the headwater and foothill zones, but are severely impacted by water abstraction in particular in the lowlands north of the Magaliesberg Biosphere Reserve. Alien Largemouth Bass (Micropterus salmoides) are also a predatory threat in some headwater locations, notably the Groot Marico Catchment (Kimberg et al. 2014) and are responsible for reduced ranges and extirpations from some historical localities for example Marico Eye. Severe recent droughts have also reduced the present number and extent of locations causing fluctuations in area of occupancy (AOO) rather than permanent loss of habitat.
Conservation
Maintenance of flows in key streams is needed, particularly in the Crocodile (West) and Elands River Catchments. Land and aquatic habitat conservation and preventing alien fish stocking.
[@book{2426,
address = {Gland, Switzerland and Cambridge, UK},
author = {Baillie, J. and Groombridge, B.},
publisher = {International Union for Conservation of Nature},
title = {1996 IUCN Red List of Threatened Animals},
year = {1996}
}
,@book{2426,
address = {Gland, Switzerland and Cambridge, UK},
author = {Groombridge, B.},
publisher = {IUCN},
title = {1994 IUCN Red List of Threatened Animals},
year = {1994}
}
,@electronic{2426,
address = {www.iucnredlist.org},
author = {IUCN},
title = {The IUCN Red List of Threatened Species. Version 2017-3},
year = {2017}
}
,@article{2560,
author = {Skelton, P.H.},
journal = {African Journal of Aquatic Science},
pages = {1--7},
title = {Name changes and additions to the southern African freshwater fish fauna},
year = {2016}
}
,@article{2560,
author = {Yang L, Sado T, Hirt MV, Pasco-Viel E, Arunachalam M, Li J, Wang X, Freyhof J, Saitoh K, Simons AM, Miya M, He S and Mayden, RL},
journal = {Molecular Phylogenetics and Evolution},
pages = {97--116},
title = {Phylogeny and polyploidy: Resolving the classification of cyprinine fishes (Teleostei: Cypriniformes)},
volume = {85},
year = {2015}
}
,@article{2581,
author = {Kimberg PK, Woodford DJ, Roux H, Weyl OLF. },
journal = {African Journal of Aquatic Science },
pages = {451--458},
title = {Species-specific impacts of introduced largemouth bass (Micropterus salmoides) in the Groot Marico Freshwater Ecosystem Priority Area},
volume = {39},
year = {2014}
}
,@phdthesis{2581,
author = {Kindler DH. },
school = {University of Johannesburg},
title = {An assessment of the reproductive biology of the Marico barb Barbus motebensis (Steindachner 1894) from the upper Groot Marico catchment},
year = {2015}
}
,@article{2581,
author = {Van der Walt KA, Swartz ER, Woodford DJ, Weyl OLF},
journal = {Koedoe - African Protected Area Conservation and Science},
title = {Using genetics to prioritise headwater stream fish populations of the Marico barb, Enteromius motebensis Steindachner 1894, for conservation action},
year = {2017}
}
,@phdthesis{2581,
author = {da Costa, LDM},
school = {PhD thesis, Universidad de Lisboa},
title = {Systematic studies on the chubbyhead barbs species complex (Osteichthyes, Cyprinidae) from southern Africa},
year = {2012}
}
,@article{2581,
author = {Engelbrecht, J.S. & van der Bank, F.H},
journal = {Water SA},
number = {2},
pages = {175--181},
title = {Allozyme differences between populations of chubbyhead barb (Barbus anoplos Weber, 1897) and Marico barb (B. motebensis Steindacher, 1894)},
volume = {23},
year = {1997}
}
,]
