Figure 1: Morphology and biomechanics of a spike from the spearing mantis shrimp L. maculata. (A) Photograph of a specimen (scale bar: 5 cm) and (B) of a raptorial appendage showing, in the white boxes, the distal spikes characterized here (scale bar: 1 cm). (C) Micro-CT reconstruction of a distal spike attached to the dactyl. The grey levels give a qualitative indication of the heterogeneous density of the cuticle (increasing density from light grey to black). (D) Micro-CT reconstruction of a single spike showing the gross morphology. Superimposed to the micro-CT are arrows having length proportional to the local curvature κ of the spike (a representative arrow indicating a curvature of 0.14 mm-1 is shown at the bottom). The inserts (yellow and orange boxes) show two typical cross-sections at the base and near the tip of the spike (scale bars: 200 µm). By comparing the two cross-sections, a slight rotation (of about 15 deg) along the main axis of the spike is evident. (E) Side view of the lateral outer border of the spike in SE-SEM showing serrations and surface grooves. (F) Spatial variations of maximum (Imax) and minimum (Imin) second area moments as well as polar moment (J) of the spike cross-sections along its length.