Fig. 10

Shell texture, crystal co-orientation strength and twinning characteristics for A. lobifera chamber walls secreted in uncontaminated (A), and in Cd²⁺- (B) and Pb²⁺- (C) contaminated waters. We show the EBSD scan, the pole figures and MUD value for the latter, the misorientations that we find in the shown scan and its 60° misorientation peak. The position of EBSD scans is indicated with white rectangles on the cuts through the shell. When compared to the shell that formed in Cd²⁺- and Pb²⁺-uncontaminated environments, we find a decrease in crystal co-orientation strength, a decrease in the 60° peak in the relative frequency-misorientation angle diagram and little to no change in degree and range of the other misorientations. In contrast to the effect of Cd²⁺ and Pb²⁺ contamination on A. lessonii shells, as for A. lobifera, the influence of Cd²⁺ and Pb²⁺ on twin formation is not as substantial. Furthermore, we do not see such a marked difference in the height of the 60° misorientation peak for Cd²⁺ and Pb²⁺.