Fig. 5. Population density effect on size and shape in Eulimnadia texana. Colours represent standardized population densities 14 days after hydration that range between 1 and 12.8 individuals/400 ml. A, Biplot of principal component scores and variable vectors (loadings) on PC1 and PC2 of a set of log-transformed linear measurements. B, Fourier shape analysis. Although the analysis is shape-only, outlines have been scaled to size for better comparison with the size plot. PC1 represents relative umbo size, while PC2 is driven by several ratios, including the H/L ratio and relative size of the dorsal margin (compare with Fig. 7).