Ancient fish defences used to inspire military armour of the future
The design of the protective scales of this primitive African curiosity is being used by the US military to help design the armour of the future. The incredible Senegal bichir (Polypterus senegalus) – a species that has barely evolved in its 96 million year existence – developed a light, multilayered set of scales to fend off the crunching bites of ferocious prehistoric predators.
When cracked or penetrated, the scale design deflects cracks to run in a circle around the wound, rather than spreading through the scale (like a crack in a windowpane). This strengthens the bichir to attacks from other predators (carnivorous attacks are not uncommon!) in the warm, shallow and muddy African river estuaries in which it lives. In fact, whilst the Senegal bichir is a popular species with aquarium keepers (often sold as a “dinosaur eel”), it’s aggressive, predatory nature means it isn’t recommended to be kept with smaller fish, which are likely to be quickly eaten!
Following research by a team from Massachusetts Institute of Technology Institute for Soldier Nanotechnologies, the US military is actively looking to learn from the way the bichir’s scale design effectively deflects impacts. Using nanotechnology, a team led by Christine Ortiz discovered multiple layers of material within each scale, which interlock to effectively protect the bichir’s soft tissues from attack. Extraordinarily, this knowledge about the structure and geometry of the bichir’s scale will be used to help design improved military armour which can better resist the impacts of war.
Unlike most fish, the Sengal bichir doesn’t possess a swim bladder – the internal gas-filled sac which aids buoyancy – instead using a primitive set of lungs to gain oxygen. This means it occasionally rises to the river surface to gulp air. Amazingly, as long as the bichir’s skin remains moist, this armour-plated curiosity can remain alive out of water for long periods of time. With poor eyesight, the fish relies on a keen sense of smell to hunt for prey in its native, muddy river habitats, aided by the large protruding nostrils you can see in the photos above.
Another fascinating curiosity for the cabinet, and one that certainly proves that biodiverse ecosystems don’t only have value in their own right, as resources, or as places for recreation. As the extraordinary case of this ‘living fossil’ shows, they may also provide unknown and unpredictable benefits for humans.
- Wikipedia page
- Reuters press release on the Sengal bichir and the US military
- The Senegal bichir at FishBase
- MIT Institute for Soldier Nanotechnologies
- Bruet et al (2008) “Materials design principles of ancient fish armour” Nature Materials 7: 748
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