Watching animals eat is like my biology crack. I don’t need it, I don’t have to do it, I don’t even always like it, but there’s just something about critters noshing on one another that renders me wonderstruck. And nothing does it for me like Beroe comb jellies:
I first saw a Beroe being badass on a research cruise. I’d overcome my seasickness to pluck through the biologist piñata candy that is a plankton tow, and pulled from the mass of wriggling bits some of my most favorite jellies in the world, along with one, lowly and sad little Beroe. Post plankton party my stomach got the better of me and I took a little “lie down”. I returned several hours later to find a single floating sack filled with my lovely jellies, all pulsing away as if no big deal, INSIDE the belly of Beroe! GAH! This simply would not fly, at least not without some money on the table. So next time I found a Beroe a colleague of mine and I decided to place a little bet. In my corner was my adopted pet named Doom of the Sea, a deadly jellyfish (called a Narcomedusa) known to eat other jellies, and in my colleagues corner, a Beroe. Before I tell you what happened, let me give you the low down on what makes Beroe jellies rainbow-making killing machines.
Basically, Beroes are swimming stomaches with mouths attached, floating around the open ocean, swallowing stuff and being scary. They are found within a strange group of animals called the ctenophores (the C is silent), which may in fact be our most distant animal cousis . But that’s not the only thing that makes Beroe strange. This is my very technically precise drawing of a Beroe’s anatomy:
Beroe have something truly unique among jellies– they have “teeth” . Check these puppies out:
These are the “teeth” of Beroe, made not out of enamel like human teeth, but out of cell hairs, called cilia. These microscopic teeth are not only sharp, they’re flexible, like this tooth digging into jelly prey:
And they don’t just have one row of teeth, but hundreds! These teeth pierce the jelly at the same time they pull it into the Beroe mouth.
So while we may see this:Jellies see this:
So as you may have guessed, my pet jelly Doom of the Sea stood no chance. With its agility and razor-like cilliary teeth, Beroe quickly introduced Doom of the Sea to the inside of its gut. I was left tallying my losses, keeping my eyes peeled to never again let a Beroe anywhere near my jellies (or cat, or fish or fingers for that matter. Those shifty little bastards…).
 Broad phylogenomic sampling improves resolution of the Animal Tree of Life. Nature. 452:745-749.
 Diversity of macrociliary size, tooth patterns, and distribution in Beroe (Ctenophora)
 Photo from http://www.visualphotos.com