Figure 3
δ15NGlu and δ15NPhe measured for L. capensis, L. bicuspidatus and N. vinctus. Trophic isoclines with a slope of 1.0 and a y-intercept interval of 7.6 represent different trophic positions (TPs = 1.0, 1.5, 2.0, 2.5, and 3.0)63,64,65,66. The “mainly autotrophy” and “mainly herbivory” TP lines were estimated from the range of nutritional states experienced by the mixotrophic kleptoplastic gastropod Plakobranchus ocellatus Maeda et al.67. The δ15NPhe of PON of sedimented diatoms for the Namibian shelf (dashed line) were back calculated from mesozooplankton δ15NPhe data of Steinkopf49 (Supplementary Table S2).
