The University of Massachusetts Amherst

In Pictures

Landmark Lobster: Cross Section Shows Vertebrate Skeletal Similarities

This composite element concentration map of a lobster cuticle is a landmark achievement for understanding the lobster's hard shell.  It demonstrates that the American lobster uses carbonate-apatite (AKA bone similar to vertebrate skeletons) as a major structural component of its cuticle.  This diverges from the long standing opinion that calcite or calcium carbonate was the major mineral contributing to the American lobster's hard cuticle.  More

The image was acquired using the Geoscience department's Cameca SX-Ultrachron electron microprobe, which uses a highly focused electron beam to generate characteristic X-rays.  The X-ray intensities can be mapped over the surface of a polished section like this lobster cuticle by either moving the sample stage, or rastering the electron beam. In this case, the image was acquired by stage motion, and the elements displayed are calcium (green), chlorine (red) and phosphorous (blue).