Life cycle stages of diverse planktonic organisms and a couple other animals that also undergo metamorphosis for comparison. Scanned from Heather L. Montgomery’s charming Little Monsters of the Ocean: Metamorphosis under the Waves.
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.
Variegated Sea Urchins (Lytechinus variegatus) can be found across the Caribbean and Western Atlantic ocean. In the wild they are mainly herbivorous, feeding on seagrass, but in captivity they can also be omnivorous. They use their tube feet for movement and for feeding.
