They may be cute and squishy-looking, but boxfishes are not very cuddly. Extremely poisonous flesh aside, these fish are also covered in amazingly strong armor.
Despite its remarkable strength, however, this armor is still flexible. This unusual and useful combination of properties has captured the imagination of scientists at the University of California, San Diego, who are studying the armor's ingenious design so that it can guide the development of new materials for human body armor and even flexible electronics.
"These damage-resisting structures have evolved for millions of years in nature and are being studied with support of the U.S. Air Force to hopefully guide us to bioinspired designs that will offer more protection against impact than our conventional ones," Marc Meyers, a professor at UC San Diego and one of two senior authors on the paper, said in a statement.
In particular, the researchers studied the shell of a type of boxfish known as the longhorn cowfish (Lactoria comuta, shown above). They report in the journal Acta Materialia that the unusual way in which the fish's hexagonal scales, called scutes, are arranged is key to these remarkable properties.
Each scale is connected to those surrounding it by the interlocking zigzag patterns along their edges, called sutures. Under normal conditions, the zigzags are not fully locked together, allowing the shell some flexibility. However, if a predator tries to chomp down on a boxfish, the scales lock into one another because of the pressure and help protect it. Most fish, in contrast, have overlapping scales such that they aren't vulnerable to bites that land between the scales.
