What do you do if you have an armour as protection and you also need to see potential predators? Chitons, molluscs with living tissues embedded in their shells, have an astounding way to reconcile the two needs: their armour is riddled with eyes! The armoured shells of chitons, therefore, serve both the purpose of protection and sight. The paper is published in the journal Science.
In a study led by researcher Ling Li and his team, the mineral-lenses eyes of the chiton species Acanthopleura granulata were analysed. The little organs are spread across its spiky, hard shell. Optical tests were conducted on each separate eye to determine whether the microscopic lenses could generate images – in other words, if they would confer on the animals the faculty of sight.
The results show that chitons can see and respond to nearby predators fast enough. However, multitasking comes with a price: it was revealed that the bigger and more complex the individual eyes became, the lower was the local mechanical performance.
On the other hand, understanding the costs entailed might help scientists to use the animals as natural models to design innovative multipurpose materials embedded with sensory capacity.