Acanthopsis is a genus endemic to southern Namibia and southwestern South Africa. Until recently the taxonomy of the group was poorly understood. As a result of a new taxonomic framework (recognising 20 species), the risk of extinction of each taxon could be reassessed and updated. This contribution presents an overview of the distribution and conservation status of the species, as well as the patterns and possible processes involved in the phytogeography of the genus. Specimen localities for all examined specimens were georeferenced and these values were used for mapping and conservation assessments. Phylogenetic relationships within Acanthopsis were studied by using sequence data from the following six gene regions: nrITS, matK, rbcL, rps16, rpl32-trnL and trnS-trnG-trnG. The group appears to have diversified in the arid mountainous semi-desert of the Richtersveld, Northern Cape, South Africa, with the vast majority (96%) of Acanthopsis taxa endemic or near-endemic to the Succulent Karoo Region (more or less congruent with the Succulent Karoo Biome). Twenty of the 23 taxa are range-restricted and have an Extent of Occurrence ≤10000 km2, with at least eight of these known from only one or two subpopulations each. Fourteen (61%) of the taxa are Red Listed as Least Concern, while 39% are Red Listed as Threatened (Vulnerable, Endangered and Critically Endangered)—mainly as a result of habitat loss due to overgrazing and trampling by domestic livestock. Although the distribution ranges of most members of Acanthopsis coincide with protected areas, the effectiveness of conservation in these regions is questionable as some protected areas are prone to overgrazing and trampling by domestic livestock. The lack of phylogenetic resolution, complex taxonomy and the high numbers of range-restricted and habitat-specific species implies recent speciation in Acanthopsis due to topography, ecological gradients and climatic conditions prevailing in the arid northwestern parts of South Africa’s Northern Cape and adjacent arid parts of southern Namibia.
A new seasonal killifish of the genus Nothobranchius is described from the Montepuez River system in northern Mozambique. The new species, Nothobranchius balamaensis Bragança & Chakona, is differentiated from congeners by its characteristic colour pattern and molecular data further support its taxonomic distinctiveness. Phylogenetic results based on two mitochondrial and three nuclear genes confirms N. balamaensis is closely related to N. kirki and N. wattersi; all three belonging to the Coastal-Inland Clade. The new species is most similar in colour pattern to N. kirki sharing the characteristic of a deep red-orange colouration in the basal, proximal, and medial zones of the caudal and anal fins that grades to orange in the distal zone. This is a key feature that distinguishes these two species from all other Nothobranchius. The main distinguishing features between the new species and N. kirki is the presence of a light blue to white band or series of irregular markings in the proximal zone of the anal fin in N. kirki, versus the absence of such a colour pattern element in N. balamaensis, as well as differences in the dorsal fin pattern. When compared to all population groups of N. wattersi, the colour pattern of N. balamaensis is distinctive. Nothobranchius balamaensis is a relatively slender member of the genus, a characteristic that clearly distinguishes it from both N. kirki and N. wattersi. Nothobranchius balamaensis is currently only known from a few specimens from the type locality.
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