An annotated checklist of the fish fauna of the river systems draining the Kahuzi‐Biega National Park (Upper Congo: Eastern DR Congo)

Abstract

The Kahuzi‐Biega National Park (KBNP), situated mainly in the Eastern Highlands Ecoregion of the Upper Congo basin, is drained by the Lowa and Ulindi rivers, and some western affluents of Lake Kivu. In this study, the first list of the fish diversity of these systems is provided based on museum collections and complemented, for the Lowa River system and the western Lake Kivu affluents, with recently collected specimens (2013–2017). A total of 118 species are reported from the Lowa basin, 22 from the Ulindi basin and seven from these Lake Kivu affluents. Within the Lowa and Ulindi, respectively, five and one species, all cichlids, have been introduced. Currently, 51 species are reported from within the park, only two of which have been reported from the highlands, i.e., Amphilius kivuensis from the Luha, the source of the Luka River, and Clarias liocephalus from the headwaters of the Lake Kivu’ affluents. With a total of 30 species, Cyprinidae is by far the largest family, representing 25% of the total species diversity of the Lowa basin. It is followed by Mormyridae with 13 species (11%), Alestidae and Mochokidae with 10 species each (8%), Clariidae and Amphiliidae with eight species (7%), and Distichodontidae with six species (5%). Seven new species for science were discovered and 11 species were found to be endemic to the Lowa system. Although further exploration is needed, this underscores the importance of the KBNP in protecting the fish fauna of the Lowa basin but also highlights the park's limited coverage of the fish fauna of the Lowa basin.

Association between Labeobarbus spp. (Teleostei: Cyprinidae) and environmental variables in the Luhoho basin (Eastern Congo River basin; DRC)

“…Nevertheless, Matthes' (1963) conclusion is supported in case he had considered as rubberlips a phenotype with hypertrophied lips and a mental lobe on the basis of the figure of L. nedgia Rüppell, 1835 that he had shown (plate ix a). Across the investigated rivers of the Luhoho this phenotype is scarce, but two specimens of similar phenotype were sampled in the basin during the fieldwork of Kisekelwa et al (2020) only over localities covered by muddy substrate. Matthes' conclusion seems to be supported by anecdotical evidence on a thick lipped specimen (developed mental lobe) of Labeobarbus holubi, now L. aeneus, from a fastflowing stretch of Vaal River that changed into a normal-lipped specimen after having been kept in a pond with muddy substrate for over a year (Groenewald, 1958).…”

“…Numerous human activities such as intensified agriculture, including palm oil exploitation in the watershed (Brown & Abell, 2005), mining and overfishing using explosives and ichthyotoxins, are threatening the Labeobarbus species in the Luhoho basin (Kisekelwa et al, 2020).…”

“…Some of these species have strongly developed or hypertrophied lips and a fleshy mental lobe on the lower jaw (referred to as the Lab.-mouth phenotype) (Figure 1a1,b1), and are called rubberlips, whereas others with a sharp cornified cutting edge on the anterior edge of their lower jaw (the Var.-mouth phenotype) (Figure 1f1,g1) are called chiselmouths. Species with an intermediate mouth phenotype also occur (Kisekelwa et al, 2020;Vreven et al, 2016Vreven et al, , 2018. In addition, some species exhibit a highly variable intraspecific mouth morphology.…”

“…The Congo basin harbours a large diversity of Labeobarbus species with a complex array of mouth phenotypes within some lineages (Katemo Manda, 2020; Kisekelwa, 2019; Kisekelwa et al ., 2020; Vreven et al ., 2018). The observed mouth polymorphism within rubbermouths, chiselmouths and their intermediates might result from two non‐exclusive phenomena: (a) hybridization between species with a Lab .‐ and Var .‐mouth morphology (Banister, 1972, 1976; Vreven et al ., 2018), or (b) an adaptation to different feeding ecologies involving differential habitat use (Oellermann & Skelton, 1990; Sibbing & Nagelkerke, 2000).…”

Biodiversity and Community Structure of Mormyridae (Pisces: Teleostei: Osteoglossiformes) from Niger River in Northern Benin: Threats, Conservation and Valorization Perspectives

“…The fishes of the Mormyridae family are of high commercial and fisheries importance and display a very large distribution in tropical Africa. These weakly electrical fishes are endemic in African riverine ecosystems and among the Osteoglossiformes, the Mormyridae is the most speciose family comprising 22 genera and about 228 species (Hopkins et al, 2007;Kisekelwa et al, 2016;Rich et al, 2017). Adjibade et al (in press) reported that the Mormyrids widely occurred in top rivers such as the Nile, Niger, Volta, Senegal, Zambezi, Gambia, Oueme, Mono etc.…”