Fishes of the Mfimi River in the central Congo basin of the Democratic Republic of Congo. Kasai ecoregion or part of the Cuvette Centrale?

Melanie L J Stiassny,Tobit L D Liyandja,S Elizabeth Alter,Myriam Y Modimo,Raoul J C Monsembula Iyaba

doi:10.15560/17.6.1681

Abstract

Despite the cultural and economic importance of fisheries to communities in the region, the Mfimi is one of the least well-documented river systems in the central Congo basin. Here we present a preliminary listing of species collected during two surveys sampling 35 sites along the main channel, in major tributaries, and in some marginal habitats. A total of 2195 specimens representing 141 species were collected and archived at the American Museum of Natural History, New York, and in the teaching collections of the University of Kinshasa. Five species are considered as potentially new to science, and range extensions of numerous species into the Mfimi are recorded. Based on the data presented we conclude that the fish communities in the Mfimi share affinities with those of the Cuvette Centrale to the north, rather than the Kasai basin with which the river is currently connected via an inflow at the Kwa-Kasai junction.

Highlights

Due to its current connection with the Kwa-Kasai, the Mfimi/Lukenie River (Fig. 1) is considered part of the large southern Kasai basin rather than of the adjacent Cuvette Centrale located to the north (Thieme et al 2005; Abell et al 2008; Brummett et al 2011)
The IUCN assessment is a compilation of point data drawn from Stiassny et al (2007) and from legacy collections housed in the Africa Museum, Tervuren (MRAC) and the American Museum of Natural History, New York (AMNH) reviewed by taxonomic experts prior to publication (Darwall and Smith 2011)
While these comparative data are minimal for the Mfimi River itself, they do provide estimated ranges for fishes from the Kasai main channel and major tributaries, and to a limited extent for the Cuvette Centrale, and the main channel of the Congo River

Summary

Introduction

Due to its current connection with the Kwa-Kasai, the Mfimi/Lukenie River (Fig. 1) is considered part of the large southern Kasai basin rather than of the adjacent Cuvette Centrale located to the north (Thieme et al 2005; Abell et al 2008; Brummett et al 2011). No ichthyological publications exist for the Mfimi (or Lukenie, or Lake Mai Ndombe), and its species composition is so poorly documented that hypotheses of the affinities of its ichthyofauna, and that of the central Congo’s largest lake, Lake Mai Ndombe, remain speculative (Thieme et al 2005). To remediate this near-total lack of information we provide a list of fishes collected during two surveys in the Mfimi basin, made during August 2015 and July 2018, at the height of the main dry season. The climate is humid and tropical, with a main dry (mid-May through August) and rainy season (September through mid-January), and an annual temperature ranging from 25–30 °C

Methods

Results

Conclusion