Stripped Robber (Brycinus lateralis) is a small predatory characin (Murray and Stewart 2002). Globally it is widespread from the Zambezi and Okavango systems, and Cunene and Busi Rivers to the St. Lucia catchment in South Africa. In South Africa it occurs in the St. Lucia wetland catchment including the Mkuze, Hluhluwe and iMfolozi rivers in Maputuland (Crass 1964, Skelton 2001). These rivers and their tributaries are seasonal. During dry, low rainfall hydrological cycles the specie takes refuge in numerous freshwater pans associated with the lowland river portions of these rivers, excluding the saline St. Lucia Lake. The species is threatened by extensive dryland agriculture that results in low water quality and quantity and increased sedimentation. Further, the species is impacted by commercial irrigated agricultural activities associated with the Mkuze community where water quality, including eutrophication and excessive flow reductions affect habitat availability and quality. These agricultural activities are causing the reduction of instream and riparian habitat diversity, and eutrophication benefiting the growth of nuisance- and invasive alien plants. Alien fishes such as species of bass (Micropterus spp.) have also been observed within the range of Stripped Robber and pose threats such as competition and predation. The species is known from an extent of occurrence (EOO) of 5,476 km2, an area of occupancy (AOO) of 116 km2 and between 11 to 12 locations as defined by threat distribution. The species qualifies as Near Threatened nationally, due to its EOO, AOO sizes and continuous decline in habitat quality meeting the criteria for Vulnerable, however there are more than 10 locations currently known. Since this is a regional assessment at the national level, a regional adjustment has been considered, however the closest neighbouring population is almost 1200 km away in the Zambezi River catchment, and there is no migration between the populations, the species status is thus not adjusted, and it is assessed as Near Threatened B1b(iii) + B2b(iii) nationally.
Distribution
The species occurs in the St. Lucia catchment area in Kwazulu-Natal, South Africa. It also occurs in the Zambezi and Okavango systems, Cunene and Busi rivers and in East Africa the species occurs in the Lower Shire River, Malawi.
Currently little is known about the population, however, habitat degradation is continuous and a decline in population size is suspected.
Threats
The major threats include habitat alteration associated with commercial agriculture (sugarcane plantations) and subsistence agriculture such as over-abstraction, eutrophication and sedimentation. Poor local land use has altered the integrity of local instream habitats that affect the refuge habitats of the species through excessive sedimentation, and reduced flows affecting connectivity of the wetted perimeter of the pans with marginal vegetation. During extreme low flows local communities cultivate exposed banks of refuge pans, resulting in additional sedimentation. Reduced flows in the river and associated sedimentation processes affects the depth and substrate of the rivers which is impacting on habitat quality. Habitat loss and sedimentation also affects the macro invertebrate communities which Stripped Robber depend on. Plant invaders, for example Water Hyacinth (Eichhornia crassipes), may impact this open water species, by limiting its habitat. There are synergistic impacts between the drought of 2015/2016 and the above mentioned threats. Invasive alien fish are also a concern to the wellbeing of this species.
Conservation
Part of this species distribution is within the borders of Protected Areas, however there is no specific conservation actions aimed at this species specifically.
[@article{18475,
author = {Skelton, P.H.},
title = {A Complete Guide to the Freshwater Fishes of Southern Africa},
year = {2001}
}
,@book{18475,
address = {Pietermaritzburg},
author = {Crass, R.S.},
publisher = {Shuter and Shooter},
title = {Freshwater Fishes of Natal},
year = {1964}
}
,@book{63287,
author = {Bell-Cross, G. and Minshull, J.L.},
publisher = {National Museums and Monuments of Zimbabwe},
title = {The fishes of Zimbabwe},
year = {1988}
}
,@article{60749,
author = {Murray, A.M. and Stewart, K.M.},
journal = {Canadian Journal of Zoology},
number = {11},
pages = {1887--1899},
title = {Phylogenetic relationships of the African genera <i>Alestes</i> and <i>Brycinus</i> (Teleostei, Characiformes, Alestidae)},
volume = {80},
year = {2002}
}
,@article{60749,
author = {Booth, A.J. and McKinlay},
journal = {African Zoology},
number = {1},
pages = {31--40},
title = {Spatial aspects of the reproductive and feeding biology of the striped robber, <i>Brycinus lateralis</i> (Pisces: Characidae), in the Okavango Delta, Botswana},
volume = {36},
year = {2001}
}
,]
