Dr. Yara Haridi

If the odontode has nerves going to it, then at least that's step one of it being innervated.

And these odontodes in our early fish from the middle Ordovician have pulp cavities and pulp cavities are where the nerve goes.

And we were able to trace it all the way down to know that like there had to have been a nerve there.

But do modern odontodes outside the mouth have nerves?

So went, collected a bunch of these algae-eating plecos, learned how to keep an aquarium because God knows I never had an aquarium, and bred a bunch of these little fish.

And then we use this amazing method called clarity where you make the little embryos super clear.

You basically remove all the...

Fats and lots of the proteins.

And then you add antibodies that attach only to nerves.

And then they have a fluorescent probe.

So they glow under a microscope.

So you bathe them in these antibodies and put them under the microscope.

And then they glow wherever the nerves go.

And you can trace every nerve to every odontoid.

All their odontoids were innervated right into the pulp cavity.

They have chikadontodes that are on this like... Catfish are really weird, guys.

I'm just going to side note everybody.

I think, what is it?

One in five vertebrates is a catfish?

Their diversity is wild.