The longhorn cowfish, from the boxfish family, can be found in tropical and subtropical waters in the Pacific and Atlantic oceans. Its shell is a good example of a material that is both light and tough. It is made of mineralized scales that do not overlap and are held together by zipper-like connections. The scales rest on a bed of fibers that imparts flexibility to the fish's carapace. These gold-on-black images were taken with micro-computed tomography.