SEM images of the nacreous pearl with unusual tablet growth.

<p>(A) The surface of the pearl at low magnification. The numbers and arrows indicate the serial section sequence and the sectioning plane of the pearl sac tissue stained by ISH referred to in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0052372#pone-0052372-g008" target="_blank">Fig. 8</a>. (B) SEM micrograph of the surface near point B in panel A. The process of tablet growth was different from a typical nacreous pearl shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0052372#pone-0052372-g003" target="_blank">Fig. 3A</a>. (C) Enlarged image of the pearl surface around point C in panel A. (D) A partial cross-section showing the lamellar structure beside the scratch. (E) The surface structure of B shown at higher magnification. Note doughnut-shaped structures. (F) Ring like structure of the growing nacreous tablets between points B and C in panel A. Scale bars are 1 mm in A, 10 µm in B and C, and 100 µm in D–F.