Fig. 2
Fish with an underbite leave a greater number of tooth marks in bite impressions compared to fish with an overbite. Surface fish (A, E) make bite impressions with fewer tooth marks (mean = 6.7) compared to cavefish (mean = 10; p < 0.01) (B, F, L). Accordingly, F2 hybrids with an overbite (C, G) left fewer tooth marks (mean = 5.6) than F2 hybrids with an underbite (mean = 8.6; p < 0.05) (D, H, L). F2 hybrids with an underbite have significantly longer lower jaws (LJ) (normalized length; p < 0.05) (I) and an increase in lower jaw tooth number (p < 0.001) compared to F2 hybrids with an overbite (K). There was no significant difference between upper jaw (UJ) tooth number between the two hybrid groups (J). White scale bar set at 1 mm