Fig. 4

Variation in body size and body shape in 24 populations of Arctic charr (Salvelinus alpinus) found in lava caves, Iceland. Fork length in millimeters (y axis) was used as a measure of body size. Body shape of individuals was obtained from landmarks-based geometric morphometrics using Procrustes linear models. Thin plate splines deformation grids (surimposed to the y axis at both extremes) show the deviation from the overall consensus shape with a 2-time magnification. Total sample size per cave ranged from 5 individuals in cave 8 to 56 in cave 25. The charr morph from the lake is refered to as Krús. Each cave is colored according to its genetic clusters as per Fig. 1