DR KEITH WHEELER / SCIENCE PHOTO LIBRARY DR KEITH WHEELER / SCIENCE PHOTO LIBRARY
Sea urchin spine. Phase contrast light micrograph of a transverse section through the concentric and radial structures of an Echinus sea urchin spine (centre of spine towards lower left). Sea urchins are marine invertebrates. Their spines consist of calcareous radial plates embedded in a reticulate calcareous and organic matrix. The concentric layers indicate the age of the spine, in a manner similar to that of the growth rings of trees. The spines of a sea urchin are designed to protect it from predators, and some of the spines carry poison glands. Magnification: x37 when printed at 10 centimetres wide.
Model release not required. Property release not required.