Aristotle's Lantern

I remember the first time I was in Mexico City, I sat down at Contramar and went to order the seasonal ceviche. After a quick under the table Google translate, I was in deep debate as to whether or not I was going to eat raw hedgehog.

I decided "yes" and ordered it.

To my relief, sea urchin was served. The name "urchin" is an old word for hedgehog, which sea urchins resemble. On retrospect, sea urchin would have been the logical conclusion, seeing as I was at a seafood restaurant. Oh well.

These are strange and incredible sea creatures.

They have a spherical body with five equal body segments, covered in long movable spines. These spines are used for movement, trapping food floating by, and as a passive defense against predators. It has tube feet located between the spines that are extensible and sucker-tipped, used also for movement, capturing food, and for attaching to surfaces.

Its mouth is a complex dental apparatus referred to as Aristotle's Lantern, consisting of a five-pointed jaw. Sea urchins use this to scrape food off of rocks, but in some occasions can use their jaw to excavate hiding spots in rocks. Powerful!

The mouth is referred to as Aristotle's Lantern, because it reminded Greek philosopher Aristotle of horn lanterns, lanterns that had five panes of thin pieces of horn to allowed light to shine out while protecting the candle from wind.

Dr. Cristina Allen ND