Title:Biodiversity and ecology of the ichthyofauna of the Central and Upper Congo basin: a case study in the region of the Wagenia falls

The general goal of this project is to study the fish diversity and ecology of the Congo basin around Kisangani. A comparison will be made between locations above and below the Wagenia (Boyoma) falls. These series of rapids are generally regarded as the ichthyological barrier between the Upper and Central Congo, a hypothesis that has never been put to the test though. Moreover, it has never been investigated whether the presumed species shift is sudden or gradual.

For the biodiversity part, we study the species with morphometric and molecular techniques (COI sequences, collaboration with lab of Dr. Erik Verheyen, KBIN). We will compile identification keys for those taxa for which no keys are available and will describe new species and redescribe species as needed. We will calculate diversity indices to quantify and compare the fish diversity between localities up- and downstream of the Wagenia falls, and between different habitat types (grass vs. tree coverage).

For the ecological part, habitat preference will be investigated by analysing the relation between species distribution and the physicochemical parameters (pH, temperature, oxygen content, conductivity, maximal depth, turbidity, water velocity, shading and substrate type) in the two different habitat types. Short term diet analysis has been conducted by analysing stomach contents and niche breadth, niche overlap, and feeding strategy has been calculated for selected species. Currently we are collaborating with the lab of Prof. dr. Steven Bouillon (KU Leuven) for stable isotopes analysis on carbon and nitrogen isotopes. This method is used to investigate the diet of fish over a longer term, and will allow us to trace back the food (carbon) source and the tropic level (nitrogen) of fishes. These data will be compiled to construct a first ever food web for this region.

Duration: begin : 2009 - end : 2013
Staff: Jos Snoeks
Tuur Moelants
Emmanuel Vreven
Phone:32 2 769 5628

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