Morphology
Lip size. Principal component analysis confirmed significant divergence between sympatric pairs of lipped and generalized ecomorphs in PC1 and PC2 space in all studied rivers (Fig. 3A). In three of the six ecomorph comparisons non overlap was detected and the distributions in PC-space were only weakly overlapping for other three comparisons of sympatric ecomorphs. PC1 explained from 45.4 (Sore R.) to 71.7% (Didessa R.) of the variance, while PC2 explained less than 36%. Eigenvectors of the characters for all PCs are given in Supplementary Table S2.  Middle lobe length (MLL) and upper lip width (ULW) had the highest contribution to divergence of sympatric ecomorphs.