A review of the biology and status of Cape Fold Ecoregion freshwater fishes

Abstract

1. Mediterranean climate regions are globally recognized as hotspots of endemism in fishes; however, these unique assemblages are increasingly threatened by human mediated impacts including water abstraction, damming and non-native species introductions.2. The Cape Fold aquatic ecoregion (CFR) of South Africa supports an assemblage of range-restricted endemic freshwater fishes, the majority of which are conservation priorities because they are under severe threat of extinction. Effective conservation and management are constrained by the lack of readily available information on this imperilled group of fishes because research efforts over the last century have been temporally disjointed and relatively uncoordinated.3. This review provides an exhaustive appraisal of published literature on the taxonomy, biogeography, life history, ecology and physiology of freshwater fishes in the CFR, and the human impacts that affect them. Its aim is to direct future research needs for effective management and conservation of this imperilled group. 4. Only 103 peer-reviewed articles on CFR fishes were recorded and the majority of available research is on taxonomy and biogeography (40.8%), followed by ecological investigations (22.3%), conservation (19.4%) and human impacts (17.5%). 5.Despite a plethora of studies on taxonomy and biogeography, recent genetic evidence suggests that fish diversity in the CFR has been severely underestimated and requires urgent attention. Human impacts severely threaten the existence of many native CFR fishes and require further study. Information on the biology and ecology of CFR fishes is limited to studies on selected species; of particular note is the lack of physiological information which is particularly pertinent given projected climate change scenarios.

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

“…The existence of such high taxonomic diversity within a small portion of the Eastern Afromontane Region is consistent with findings from a number of previous studies that have uncovered substantial hidden diversity and narrow range endemic species (or lineages) within several stream fishes that were previously thought to have wide geographic ranges in southern Africa (e.g., Goodier et al 2011;Maake et al 2014;Morris et al 2015;Swartz et al 2007Swartz et al , 2009Wishart et al 2006). Results of the present study thus add to the growing board of evidence that shows that a large proportion of freshwater fishes in southern Africa remain scientifically undocumented, because many river systems remain poorly explored as much of the previous research effort and application of molecular approaches has predominantly focussed on fishes of the Cape Fold Ecoregion (Ellender et al 2017). Despite being one of the geographically and taxonomically well explored regions in southern Africa, new species and deeply divergent genetic lineages continue to be discovered within almost all fish taxonomic groups of the Cape Fold Ecoregion Chakona and Skelton, 2017;Chakona et al , 2014Wishart et al 2006), and estimates indicate that there are about 43 undescribed species within the 21 currently recognised fish species of this region (Linder et al 2010).…”

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)

“… In addition, indirect impacts on native fishes include competition for food and habitat by other non‐native fish species, such as banded tilapia ( Tilapia sparrmanii ) , common carp ( Cyprinus carpio ) and smallmouth yellowfish ( Labeobarbus aeneus ) . At present 60% of the formally described freshwater fish species in this region are listed under highly threatened categories of the IUCN red list of threatened species . Ecological studies for many of these native fishes thus requires considerable effort to minimise lethal sampling approaches.…”

“…[56][57][58] At present 60% of the formally described freshwater fish species in this region are listed under highly threatened categories of the IUCN red list of threatened species. 55 Ecological studies for many of these native fishes thus requires considerable effort to minimise lethal sampling approaches. Hence, the application of SIA for trophic ecology studies in this region requires an evaluation of the use of nonlethal alternatives to muscle tissue on aspects such as isotopic turnover rates and DTDFs.…”

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

“…Results of the present study thus add to the growing board of evidence that shows that a large proportion of freshwater fishes in southern Africa remain scientifically undocumented, because many river systems remain poorly explored as much of the previous research effort and application of molecular approaches has predominantly focussed on fishes of the Cape Fold Ecoregion (Ellender et al 2017). Despite being one of the geographically and taxonomically well explored regions in southern Africa, new species and deeply divergent genetic lineages continue to be discovered within almost all fish taxonomic groups of the Cape Fold Ecoregion (Chakona and Swartz, 2013; Chakona and Skelton, 2017; Chakona et al 2013, 2014; Wishart et al 2006), and estimates indicate that there are about 43 undescribed species within the 21 currently recognised fish species of this region (Linder et al 2010).…”