Micro-CT Scanning of Contrasted Animal Heads

Micro-CT scans were performed using an X-ray microscope (Xradia MicroXCT-200; Carl Zeiss Microscopy GmbH, Jena, Germany) that uses a 90-kV/8 W tungsten X-ray source and switchable scintillator-objective lens units as described by Sombke et al. (2015) (link). The heads of fixed animals (Bouin; two specimens) were contrasted in iodine solution (2% iodine resublimated (Cat. #X864.1; Carl Roth GmbH, Karlsruhe, Germany) in 99.5% ethanol), critical point-dried using a fully automatic critical point dryer Leica EM CPD300 (Leica Microsystems, Wetzlar, Germany) and scanned dry (scan medium air). Tomography projections were reconstructed using the reconstruction software XMReconstructor (Carl Zeiss Microscopy GmbH, Jena, Germany), resulting in image stacks (DICOM format) with a pixel size of about 5.8 µm for the 4 × objective and 1.9 µm for the 10 × objective.