Project R-14534

The algal flora of the Albertine Rift Lakes. Using stomach content analyses to compare of the dietary overlap of herbivorous fishes in native and introduced conditions, with a focus on diatom taxonomy. (Research)

Lakes of the Albertine rift (East Africa) harbour valuable fisheries resources that are of significant socioeconomic importance for local communities. These lakes are inhabited by various herbivorous fish species, including the nile tilapia, Oreochromis niloticus, which forms the basis for extensive fisheries and which is of major importance for aquaculture. In several of these lakes, Nile tilapia co-occurs with a smallerbodied congener, Oreochromis leucosticus, as well as with herbivorous species of Haplochromis, although it is still unknown to what degree these species occupy different ecological niches. In spite of their economic importance, the diet of these fishes has hardly been studied. I will study the gut contents of Oreochromis niloticus, Oreochromis leucosticus, and Haplochromis spp. to investigate dietary overlap. Additionally, I will check whether this overlap in diet is larger in lakes where tillapias were introduced, than in lakes were they occur naturally. For this, I will focus on diatoms. Species in these group are not only form an important component of the algal community, but they also have a sturdy siliceous cell wall. This allows them to still be identified even after other prey items have been digested. I will also make an overview of the diatom fauna of these lakes, and provide species descriptions that will be backed with molecular data.

01 September 2023 - 31 August 2027