Fig. 7
The microstructure of the worm bioconstruction is made up of three main sectors: the circular void of the worm; the tube that is built by the worm capturing sand grains (above: in white; below: in red); and, the sediments that are deposited between adjacent tubes (intertube; in grey in above). Above, an image taken under the microscope with crossed nicols; below, an image in which the three main sectors with the three different colors are highlighted