Connection between shape and DOC concentrations.

<p>Correlation between scores of Discriminant Function Analysis between perch caught in the littoral and pelagic zone and DOC concentrations. Spearman’s rank correlation coefficient is shown. ** <i>P</i><0.005.</p

Main characteristics of the surveyed lakes in Central Sweden.

<p>Main characteristics of the surveyed lakes in Central Sweden.</p

Results of shape analyses of perch caught in the field.

<p>Shape differences between littoral (black line) and pelagic (grey line) perch of the six lakes studied. Positions of the 16 digitized landmarks used in geometric morphometrics are shown. Shape-change outlines of Discriminate Function Analysis are magnified ten-fold.</p

Results of experiments on foraging efficiency.

<p>Results of experiments on foraging efficiency.</p

Graphical representation of results from experiment on perch foraging efficiency.

<p>Results of A) foraging on <i>Daphnia</i>, representing pelagic prey and B) foraging on Ephemeroptera as littoral prey of perch phenotypes (pelagic and littoral) under different visual conditions (clear water, brown water). Average number of prey items captured per second are shown (± SE).</p

2D nMDS of fatty acid composition.

<p>Two-dimensional representation of non-metric multidimensional scaling (nMDS) of fatty acid composition (%) of perch caught in the littoral and pelagic zone of the six lakes surveyed. Color shading illustrates the gradient of DOC from light blue = low DOC to dark brown = high DOC. Relative length of vectors from fatty acids identified to contribute most to observed difference in composition between perch caught in clear-and brown water-lakes depict strength in positioning in the respective dimension.</p

Results of shape analyses of perch from the laboratory experiment.

<p>Shape differences between phenotypes induced by habitat structure and feeding mode in the laboratory experiment. Phenotypes of the littoral and pelagic treatments are depicted black and grey lines respectively. Shape-change outlines of Discriminate Function Analysis are magnified ten-fold.</p

Locations of the six lakes surveyed in this study.

<p>Copyright by Lantmäteriet Gävle (2012): Permission i2012/921.</p

Connection between fatty acids and DOC concentration.

<p>Correlation between DOC concentrations and proportions of A) 22:6n-3, B) 18:3n-3, C) 20:5n-3, D) 16:1n-7, and E) 20:4n-6, which were fatty acids identified to contribute most to observed difference between composition of perch caught in clear- and brown-water lakes. Spearman’s rank correlation coefficient (r_s) is shown. ** <i>P</i><0.005; n.s. = not significant.</p

Appendix F. The parameter estimates of t-POC diets for power functions.

The parameter estimates of t-POC diets for power functions