Pink teeth

I recently came across this set of jaws from a Tortonese's stingray (Dasyatis tortonesei, which is probably invalid by the way) and was very surprised by the pink color of the teeth. It apparently not an uncommon occurrence in this species and is supposedly related to their diet, but I don't have any info/idea so far of what may be causing the the teeth to turn pink like that. For the little story, fishermen catching these apparently call them "whore rays" since they look to be wearing way too much lipstick.

D. tortonesei jaw, labial view. Scale bar: 1 cm

 D. tortonesei jaw, labial view. Scale bar: 1 cm

And while doing my regular fish shop round the other day, I found a couple of these guys.

 Red bandfish (Cepola macrophthalma) heads.

They are red bandfish, a small burrowing species found mainly in the eastern Atlantic and Mediterranean sea. First time I saw some despite them being regularly caught for those. They should have nice little skulls, and I might try to clear and stain a couple as well, more on that later.