Scanning electron microscopy (SEM) and 3D visualization
For documentation of morphology using SEM, three radulae were carefully
extracted and cleaned by a short ultrasonic bath in 70% EtOH.
Subsequently they were mounted on SEM specimen holders by double-sided
adhesive carbon tape and sputter-coated with platinum (5 nm layer). For
visualization, we used a SEM Zeiss LEO 1525 (One Zeiss Drive, Thornwood,
NY, USA). Only mature teeth from the working zone, which can be
identified by lack of covering epithelia, were studied. To document the
wear on the teeth, radulae were rewetted by 70% EtOH afterwards,
cleaned by a short ultrasonic bath, rearranged on SEM sample holders and
visualized again in the SEM. Nomenclature of teeth was adapted from (Ong
et al., 2017).
For the 3D visualization, mature radular teeth of the working zone of
two radulae were extracted manually with foreceps. Each tooth was
mounted on SEM specimen holders by double-sided adhesive carbon tape,
sputter-coated with platinum (5 nm layer), and visualized under the SEM
from all sides. Using the 3D software Blender v2.83 (Blender
Foundation), the teeth were then modelled by hand always comparing the
3D visualization with the SEM images taken from different sides (see
also protocol in Krings et al., 2020, 2021e). In the same manner, the
position and embedment of the teeth within the membrane were
reconstructed.