Figure 8

Trade-offs between phenotypic traits in response to salinity. Bi-plot from canonical analysis of principal coordinates (CAP) on barnacles from three populations, exposed to different salinity treatments (grouped by salinity). The first canonical axis explained 68% of the variation whereas the second axis only explained 15%. Vectors (lines) indicate the influence of different phenotypic traits in explaining the differences in responses between salinities (correlations are scaled by multiplying the original value by 0.5 to fit plot size). The phenotypic traits included are: Gomp_a, Gomp_b, Gomp_c (Gompertz growth parameters; see methods), AW (=ash weight), DW (=dry weight), AFDW (=ash-free dry weight), CI (=condition index), shell strength, % Mature and % Fertilized (=proportion of barnacles with mature gonads vs. fertilized eggs).