“…Besides of Ca, Cl, and P, the following elements, that are not the basis of chitin and probably reinforce the cuticle, were previously detected in the cuticle of crustacean: Mg 50 , 51 , 55 , 69 , 78 , 81 , 88 ; S, K, Br, Zn, Cu, Fe, and Ni in copepod mandibles 72 ; Cu and Zn in copepod mandibles 71 ; Br in amphipod mandibles 73 and isopod claws 88 ; S in shrimp claws 52 . For Procambarus clarkii , we also detected Mg, K, S, Zn, and Fe, but no Br, Ni, and Cu.…”