An integrative taxonomic review of theNatal mountain catfish,Amphilius natalensisBoulenger1917(Siluriformes,Amphiliidae), with description of four new species

Abstract

An integrative taxonomic analysis combining mitochondrial cytochrome oxidase subunit I sequences, morphology, colour pattern and two species delimitation approaches revealed the existence of five lineages within the Natal mountain catfish, Amphilius natalensis, in southern Africa. These lineages are separated by substantial genetic divergences (1.6%-9.46%), and they can be consistently distinguished from one another based on a combination of morphology and colour pattern differences.Additionally, the lineages are allopatrically distributed and confined to isolated river systems draining discrete mountain ranges, which makes gene flow among them unlikely. One of these lineages is A. natalensis s.s., which is confined to the uMngeni and Tukela river systems in KwaZulu Natal (KZN) Province in South Africa. The other four lineages represent new species to science which are described as Amphilius zuluorum sp. nov., endemic to the uMkhomazi River system in KZN, Amphilius engelbrechti sp. nov., endemic to the Inkomati River system in Mpumalanga Province in South Africa, Amphilius marshalli sp. nov., endemic to the Pungwe and Lower Zambezi river systems in Zimbabwe and Mozambique, and Amphilius leopardus sp. nov., endemic to the Ruo River in Malawi. The results show that Amphilius laticaudatus which is endemic to the Buzi River system in Zimbabwe and Mozambique, belongs to the A. natalensis s.l. complex. A redescription of A. laticaudatus is presented and an updated identification key for the mountain catfishes of southern Africa is provided.

How the Freshwater Biodiversity Information System (FBIS) is supporting national freshwater fish conservation decisions in South Africa

“…However, there are additional steps that could improve upon and update the tool, thereby supporting more effective freshwater conservation in the future. Firstly, there is an urgent need to update and resolve the taxonomy of South Africa's freshwater fishes, as there are a number of distinct genetic lineages that await formal description (Chakona et al, 2015(Chakona et al, , 2020bMartin and Chakona, 2019;Bronaugh et al, 2020;Kambikambi et al, 2021;Mazungula and Chakona, 2021;Ramoejane et al, 2021). Once the taxonomy of South Africa's freshwater fishes has been revised, the FBIS and NEST can be updated accordingly.…”

Diversity, distribution and extinction risk of native freshwater fishes of South Africa

“…The other non‐endemic genera are found throughout southern Africa, although their ranges vary (Skelton, 2001). In terms of species diversity, 64 (30%) of the 216 currently recognised species in southern Africa are endemic to South Africa (Bragança et al ., 2021; Chakona et al ., 2013; Kambikambi et al ., 2021; Maake et al ., 2014; Mazungula & Chakona, 2021; Riddin et al ., 2016; Skelton, 2001; Skelton et al ., 2018; Skelton et al ., 2021; Stauffer et al ., 2021).…”

“…Global assessments were submitted to the IUCN in 2017 for publication on the website (http://www.iucnredlist.org), whereas all national assessments were published on the SANBI national Red List website (http://speciesstatus.sanbi.org/). Taxonomic revisions that were done subsequent to the 2016 IUCN Red List assessments provided more accurate species boundaries within Amphilius natalensis , Enteromius anoplus and Enteromius pallidus (Kambikambi et al ., 2021; Martin & Chakona, 2019; Mazungula & Chakona, 2021). In the present study, the authors updated the assessments for A. natalensis s.s., E. anoplus s.s. and E. pallidus s.s. and assessed the status of three newly described species, Amphilius engelbrechti , Amphilius zuluorum and Enteromius mandelai as well as two revalidated species, Enteromius oraniensis and Enteromius cernuus (Table 1).…”

“…DNA‐based studies have identified several unique lineages or candidate species within almost all freshwater fishes studied thus far in South Africa ( e.g ., Bronaugh et al ., 2020; Chakona et al ., 2013; Chakona et al ., 2015; Chakona et al ., 2020b; Morris et al ., 2016; Wishart et al ., 2006). This has resulted in the revalidation of a number of synonyms and description of several new species ( e.g ., Chakona et al ., 2013; Chakona et al ., 2014; Chakona & Skelton, 2017; Kambikambi et al ., 2021; Maake et al ., 2014; Mazungula & Chakona, 2021; Riddin et al ., 2016) and improved understanding of species distribution ranges and the key threats (Ellender et al ., 2017; Tweddle et al ., 2009). The last comprehensive Red List Assessment (RLA) for freshwater fishes of South Africa was conducted in 2006 (Tweddle et al ., 2009).…”

“…DNA-based studies have identified several unique lineages or candidate species within almost all freshwater fishes studied F I G U R E 1 (a) Overall diversity of freshwater fishes within each of the freshwater ecoregions of South Africa: Southern Kalahari (571), Western Orange (572), Karoo (573), Drakensberg-Maloti Highlands (574), Southern Temperate Highveld (575), Zambezian Lowveld (576), Amatolo-Winterberg Highlands (577) and the Cape Fold ( 578)), and, (b) the number of threatened taxa in each of these ecoregions thus far in South Africa (e.g., Bronaugh et al, 2020;Chakona et al, 2015;Chakona et al, 2020b;Morris et al, 2016;Wishart et al, 2006). This has resulted in the revalidation of a number of synonyms and description of several new species (e.g., Chakona et al, 2014;Kambikambi et al, 2021;Maake et al, 2014;Mazungula & Chakona, 2021;Riddin et al, 2016) and improved understanding of species distribution ranges and the key threats (Ellender et al, 2017;Tweddle et al, 2009). The last comprehensive Red List Assessment (RLA) for freshwater fishes of South Africa was conducted in 2006 (Tweddle et al, 2009).…”