Figure 6 . A: Maximum likelihood SNP-based phylogeny and genetic structure of generalized and thick-lipped ecomorphs ofLabeobarbus from the different basins of Ethiopia (Genale, Didessa, Gojeb, Sore, and Birbir Rivers). The tree inferred with IQ-TREE2 using 15,820 variant SNPs with the TVM+F+ASC+R3 substitution model. Heterozygous sites within each individual were encoded using IUPAC notation. The thick-lipped individuals in the tree are depicted in yellow color. Individuals are labeled by their voucher numbers. Ultrafast bootstrap values above 70% are shown as numbers near the corresponding nodes, while the black points in the nodes designate 95-100% support. The genetic cluster proportions inferred by hierarchical STRUCTURE analysis are shown to the right of sample numbers: 1 - analysis of all samples with 2,411 SNPs revealed best K=4; 2 - analysis of the Genale genetic cluster with 7,905 SNPs revealed no further subdivision; 3 - analysis of the Didessa genetic cluster with 6,932 SNPs revealed subdivision on two clusters (best K=2) corresponding to mouth phenotypes; 4 - analysis of the Gojeb genetic cluster with 4,471 SNPs revealed no further subdivision; 5 - analysis of the Sore/Birbir (White Nile basin) genetic cluster with 2,020 SNPs revealed subdivision on two clusters (best K=2) corresponding to the river basins. B: Principal Component Analysis (PCA) plot with points representing individuals and 95% confidence intervals colored by genetic clusters inferred with STRUCTURE.