Fig. 1

The location of the study area (Gombe ecosystem) in the Kigoma region of western Tanzania (inset). The sampled streams from bottom to top are: Nyakageni in the Kibirizi area along Kigoma Bay in Kigoma town, Mtanga in Mtanga village, Kakombe and Mkenke in Gombe National Park; Ngonya in Mwamgongo, Misonga in Bugamba, and Bumba and an unnamed stream in Kiziba