Fig. 5
From: Etmopteridae bioluminescence: dorsal pattern specificity and aposematic use
Spine structure. Spine structure analyses by MRI image showing any evidence of soft tissue at the posterior side of the spine (red arrowhead) (a). Internal spine structure analyses by micro CT scan showing any evidence of a duct/canal at the posterior side of the spine hard tissue (calcified structure), red arrowhead showing the calcified tissue at the posterior side of the spine without any duct/canal (b). In both analyses, the only hollow on the spine, at the center, is filled with cartilaginous matrix