Shark-grown armour
Did you know that sharks and rays have a special kind of armour?
Unlike most fish, sharks and rays have cartilage skeletons (that’s the soft bit in between your nostrils), and these skeletons are covered in thousands of tiny, hard tiles called tesserae. These tiles form a protective shell, kind of like a built-in chainmail suit.
Cool right? But that’s not the thing we’ve learned recently.
Until now, there was a mystery. What happens when the animal grows? Do they grow new tiles to fill in the gaps? Nope. Research from Binru Yang (Max Planck Institute of Colloids and Interfaces) and colleagues reveals that as the tiles grow as the shark or ray grows.
But wait, there’s more!
Bigger tiles grow faster than smaller ones.
This means the skeleton remains fully protected without needing to rearrange any tiles or change their shapes. What’s particularly cool is that the growth of the tiles seems to adjust to the growth of the animal. The researchers think that they do this by sensing strain from the growing skeleton.
