Energy dispersive X-ray spectrum of the small posterior hook of a Neoechinorhynchus personatus specimen from Mugil cephalus in the Mediterranean showing markedly lower levels of phosphorus and calcium, and considerably lower levels of sulfur than anterior hooks (^{Fig. 37}). The X-ray data are the elemental analysis of the whole hook (see bolded figures in Table 3). Insert: SEM of a deep Gallium cut at the base of a hook.