why-animals-do-the-thing:

sea-nerd-adventures:

SUPER COOL INVERT SHENANIGANS

Sea urchins have modified mouth parts on the underside of their bodies called an Aristotle’s lantern. The lantern is made up of tooth-like plates that scrape up bits of food like algae, as seen here.

We specifically don’t scrub the algae in this habitat for the urchins, and I see them on the walls all the time, presumably getting a tasty meal. But I had never seen it in action before last week! Invertebrates are such cool little aliens!

I will always share videos of sea urchins eating, because I love the sudden appearance of shiny white tiny vampire teeth. 

Here’s a diagram of the Aristotle’s lantern structure, if you’re curious what it looks like under all the prickles.