Fig. 3

a A specimen of Sinocyclocheilus altishoulderus indicating the position of 15 landmarks (red: larger points indicated by numbers 1–15) and 180 semi-landmarks (Orange: smaller point) used for the calculation of Procrustes coordinates and traditional linear measurements (SL standard length, ED eye diameter and sED standardized eye diameter) used in the geometric morphometric analyses. b PCA showing the variation in body shape of the genus Sinocyclocheilus traced with eye morphology, habitat occupation, existence of horn. PC1 and PC2 accounts for 32% and 17% of the variance respectively. A shift from the fusiform shape of the Normal-eyed surface forms to a more “boxy” form of the Micro-eyed and Blind forms is evident