Figure 1

A) Sites of eight Tropheus populations sampled along the Zambian shore of Lake Tanganyika in August-September 2011. Black and sand-coloured shorelines indicate suitable rocky and unsuitable sand shores, respectively. Blue lines represent rivers, and the yellow line represents political borders. The six easternmost sites were resampled in August-September 2012. B) Bayesian analysis of the genetic structure of the eight populations. As previous genetic studies on these populations revealed that populations largely cluster according to colour morph [55, 56, 58, 59], colour morph was used in the analysis as prior information. The colour of each of the four cluster corresponds to the predominant colour of the assigned individuals (i.e., red/orange for Chilanga and Linangu, blue for Tumbi and Katoto, light olive for Mbita Island and Wonzye Point, and dark olive for Muzumwa and Toby’s place). C) Visualization of significant differences (after correction for multiple testing) between neighbouring Tropheus populations for infection presence, abundance, infection intensity and parasite community composition. Full bars indicate that significant differences were observed in both sampling years. Dashed bars indicate that significant differences were only observed, or only investigated, in one sampling year.