Geometric morphometrics
The body morphology of individual minnows caught in lake and stream locations was analyzed using a landmark-based geometric morphometric method (38). Digital lateral photographs were transferred to TPSdig2 (https://life.bio.sunysb.edu/morph/) and 35 landmarks were determined, including 18 homologous and 17 semi-landmarks based on proportional distances between structures (Figure 2) (39).