Scanning X-Ray Fluorescence Microscope (SXFM) image of shark vertebrae in the zinc spectrum (size not to scale) for Dusky (<i>Carcharhinus obscurus</i>), Spinner (<i>Carcharhinus brevipenna</i>), Port Jackson (<i>Heterodontus portjacksoni</i>), Smooth Hammerhead (<i>Sphyrna zygaena)</i>, Blacktip (<i>Carcharhinus limbatus)</i>, White (<i>Carcharodon carcharias)</i>, Australian Angel (<i>Squatina australis</i>), Eastern Angel (<i>Squatina albipunctata)</i>, Southern Sawshark (<i>Pristiophorus nudipinnis</i>), and Common Sawshark (<i>Pristiophorus cirratus)</i>.

<p>Results are overlayed onto Compton scatter maps, essentially an X-ray of the sample (white colour). Colours signify concentrations of zinc. Zinc concentrations are highest in the <i>intermedialis</i> in all species, the highest concentrations often occurring pre-birth. Notice the absence of colour (read: zinc) in the <i>corpus calcareum</i>, except in the Port Jackson. Birth marks indicated with red arrows.