Fig. 5

Scatterplots of the first two principal components. The principal components (PC1 and PC2) derived from 5 out of 12 kinematic parameters and illustrate differences between the three processing modes in kinematic space. Light blue, processing in the late-larval morphotype (LLM); purple, processing in the mid-metamorphic morphotype (MMM); and black, processing in post-metamorphic morphotypes (PMM) (5 shades of grey code the post-metamorphic individuals). The convex hulls display the largest possible area which contains all observations of the respective feeding mode. PC1 explains 48.1% of the total variance and is mostly defined by hyobranchial parameters, while PC2 explains 21.0% of the total variance and is most strongly defined by gape parameters (Table 3). Note that the MMM and PMM show overlap, while LLM and MMM as well as LLM and PMM show no overlap in kinematic space