Revalidation of Enteromius karkensis (Gilchrist and Thompson 1913) (Cypriniformes: Smiliogastrinae) from the southern temperate freshwater ecoregion, South Africa.

The chubbyhead barbs, a distinct group of fishes endemic to southern Africa, currently include eight valid species. Historically, Enteromius anoplus was the most widespread freshwater fish in South Africa due to synonymizations in the 1960s. It occurred in nearly every river system except coastal systems in the Cape Fold Ecoregion and the lower Orange River.

Taxonomic diversity, distribution, and ecology of the freshwater fishes of the Zambezian Lowveld Ecoregion in southern Africa: A systematic review.

The Zambezian Lowveld Ecoregion (ZLE) is one of the 22 freshwater ecoregions covering southern Africa. This ecoregion covers ~520,418 km and extends from south of the Zambezi Delta in the north to the uMngeni River basin in the south. This study aimed to compile a comprehensive synthesis of the available information on the diversity and distribution of freshwater fishes in this ecoregion based on natural history collection holdings by reviewing the published scientific literature.

Hidden in the riffles: A new suckermouth catfish (Mochokidae, ) from the middle Zambezi River system, Zimbabwe.

The recent surge in the discovery of hidden diversity within rheophilic taxa, particularly in West and East Africa, prompted a closer examination of the extent to which the current taxonomy may obscure the diversity of riffle-dwelling suckermouth catfishes in the genus in southern Africa. Currently, the region comprises eight valid species within this genus. Seven of them have relatively narrow geographic distribution ranges except for , which is considered to be widely distributed, occurring from the Buzi River system in the south, and its northern limit being the eastward draining river systems in Tanzania.

Functional diversity does not explain the co-occurrence of non-native species within a flow-modified African river system.

Globally, there is growing concern on the occurrence of multiple non-native species within invaded habitats. Proliferation of multiple non-native species together with anthropogenic-driven habitat modifications raise questions on the mechanisms facilitating the co-occurrence of these species and their potential impact within the recipient systems. Using the Great Fish River system (South Africa) which is anthropogenically-modified by inter-basin water transfer (IBWT), as a case study, this research employed trait-based approaches to explore patterns associated with the co-occurrence of multiple non-native fish species.

Allopatric differentiation in the Enteromius anoplus complex in South Africa, with the revalidation of Enteromius cernuus and Enteromius oraniensis, and description of a new species, Enteromius mandelai (Teleostei: Cyprinidae).

The chubbyhead barb, Enteromius anoplus, as currently described, is the most widely distributed freshwater fish in South Africa. The species occurs in almost all the major river systems across the country, with the exception of the small coastal drainages on the south coast. The use of a comprehensive data set of mitochondrial (mtDNA) cytochrome b (cyt b) sequences uncovered the presence of four distinct lineages or operational taxonomic units (OTUs) within E.

Deep genetic and morphological divergence in the Hippopotamyrus ansorgii species complex (Teleostei: Mormyridae) in southern Africa.

The present study used molecular and morphological approaches to investigate hidden diversity within the Hippopotamyrus ansorgii species complex in southern Africa. Phylogenetic reconstructions and three species delimitation methods based on two mitochondrial markers (cytochrome b and cytochrome oxidase I) and one nuclear marker (S7) revealed 12 Molecular Operational Taxonomic Units (MOTUs), with two of them representing two recently described species, Hippopotamyrus longilateralis and Hippopotamyrus szaboi. The highest diversity occurred in the Kwanza River system, which contained five MOTUs, and the Upper Zambezi River system that had two MOTUs.

Distribution patterns and habitat associations of Sandelia bainsii (Teleostei: Anabantidae), a highly threatened narrow-range endemic freshwater fish.

Sandelia bainsii is a range-restricted and highly threatened freshwater fish endemic to South Africa. Recent genetic evidence suggests that this species comprises three allopatrically distributed lineages that have been informally designated as Sandelia sp. "Kowie," Sandelia sp.

Exploring source differences on diet-tissue discrimination factors in the analysis of stable isotope mixing models.

Stable isotope mixing models are regularly used to provide probabilistic estimates of source contributions to dietary mixtures. Whilst Bayesian implementations of isotope mixing models have become prominent, the use of appropriate diet-tissue discrimination factors (DTDFs) remains as the least resolved aspect. The DTDFs are critical in providing accurate inferences from these models.

Environmental niche patterns of native and non-native fishes within an invaded African river system.

To test ecological niche theory, this study investigated the spatial patterns and the environmental niches of native and non-native fishes within the invaded Great Fish River system, South Africa. For the native fishes, there were contrasting environmental niche breadths that varied from being small to being large and overlapped for most species, except minnows that were restricted to headwater tributaries. In addition, there was high niche overlap in habitat association among fishes with similar distribution.

The influence of diet composition and tissue type on the stable isotope incorporation patterns of a small-bodied southern African minnow Enteromius anoplus (Cypriniformes, Cyprinidae).

Rationale: In trophic ecology, the use of stable isotope data relies on the general understanding of isotope turnover rates and diet-to-tissue discrimination factors (DTDFs). Recent studies on the application of stable isotope data have shown that isotope turnover rates and DTDFs can be influenced by many factors, including diet composition and tissue type. This study investigated the influence of diet composition and tissue type on stable isotope incorporation patterns in a small-bodied African minnow, the chubbyhead barb Enteromius anoplus.

Evidence of hidden diversity and taxonomic conflicts in five stream fishes from the Eastern Zimbabwe Highlands freshwater ecoregion.

Stream fishes of the Eastern Afromontane region are among the least studied vertebrates in this region, despite the potential for harbouring cryptic diversity. The present study examined mitochondrial cytochrome oxidase subunit I (COI) sequence divergence in 153 specimens of stream fishes belonging to four genera and three families, [( and (Amphiliidae); (Mochokidae); and (Mormyridae)], in the Eastern Zimbabwe Highlands (EZH) freshwater ecoregion to explore the extent to which the current taxonomy conceals the ichthyofaunal diversity in the region. The General Mixed Yule Coalescent (GMYC) species delineation method identified 14 clusters within five currently recognised 'species' from the EZH ecoregion.

Swimming with the giant: coexistence patterns of a new redfin minnow from a global biodiversity hot spot.

Ecological niche theory predicts that coexistence is facilitated by resource partitioning mechanisms that are influenced by abiotic and biotic interactions. Alternative hypotheses suggest that under certain conditions, species may become phenotypically similar and functionally equivalent, which invokes the possibility of other mechanisms, such as habitat filtering processes. To test these hypotheses, we examined the coexistence of the giant redfin , a newly described freshwater fish, together with its congener and an anabantid by assessing their scenopoetic and bionomic patterns.

Alternative responses to predation in two headwater stream minnows is reflected in their contrasting diel activity patterns.

Animals exhibit diel periodicity in their activity in part to meet energy requirements whilst evading predation. A competing hypothesis suggests that partitioning of diel activities is less important because animals capitalise on opportunity. To test these hypotheses we examined the diel activity patterns for two cyprinid minnows, chubbyhead barb Barbus anoplus and the Eastern Cape redfin minnow Pseudobarbus afer that both occur within headwater streams in the Eastern Cape, South Africa.