#yay for new reasons to love fluoride dental care

[miles-of-heart]

You know the beak of the parrotfish, right?

While researching for upcoming fish facts I ended up going down a rabbit hole on parrotfish teeth, and I need to share this information in another form than just a fish fact. This stuff is unbelievable. You know the beak of the parrotfish, right? It's formed from the fused teeth of the parrotfish, as an adaptation to have ample biting surface to scrape off and chew on coral, their main food source.

A close-up of the beak of a parrotfish. It has this honeycomb pattern which I find very cool.

Well. To constantly chew on coral, they must have some pretty hard teeth, right? And they indeed do: the teeth of the parrotfish are made up of a mineral called fluorapatite, which forms intricate, chainmail-like woven structures on a microscopic level. Fluorapatite just so happens to be the second hardest biomineral found. This stuff, the parrotfish's teeth?? They are stronger than copper, silver and gold. That's crazy, right!!?? A square inch of the parrotfish's teeth can withstand a whopping 530 TONS OF PRESSURE!! That's the weight of 88 ELEPHANTS on top of a single square inch!!!! The only biomineral that is tougher is the teeth of chitons, that is the single tougher thing in the whole world!!! Not only that, but the stiffness and hardness of the teeth increases the more we get closer to the tip (as the mineral fibers get closer and closer to one another), the very tips of the teeth even surpass the chiton teeth in stiffness!!!

Here are pictures produced through a process called PIC mapping, which shows the size and orientation of crystal fibers at the tip of the teeth.

That feels like it shouldn't be right, no? You'd think that the toughest biominerals in the world would belong to, like, the skull of an animal that rams into rocks or maybe the shell of some animal, not the teeth! The teeth of chitons and parrotfish out of all animals no less! Who would've guessed that the diet of "rock animal" would make the parrotfish require some of the toughest dentition the world has ever seen, huh? That right there is one super good reason why you should never stick your finger in the mouth of one.

Every day I am blown away by how amazing fishes are....