Jelly video: the comb jelly Beroe (aka the Rainbow Jelly of DEATH)

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:

This amazing video is from the youtube site of scidivervideo

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 [1].  But that’s not the only thing that makes Beroe strange.  This is my very technically precise drawing of a Beroe’s anatomy:

Beroe, like most Ctenophores, have comb rows they use the paddle along (the combs of ctenophores spilt up light like crystal prisms, that's why they have rainbows on their bodies), and an apical organ that helps them determine up and down.

Beroe, like most Ctenophores, have comb rows they use the paddle along (the combs of ctenophores spilt up light like crystal prisms, that’s why they have rainbows on their bodies), and an apical organ which helps coordinate their movement.

Beroe have something truly unique among jellies– they have “teeth” [2].  Check these puppies out:

ctenophore teeth

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:

ctenophore tooth

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.

comb jelly teeth

So while we may see this:

I'm so cute I love you! (from


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…).   

Work Cited:

[1] Broad phylogenomic sampling improves resolution of the Animal Tree of Life. Nature. 452:745-749.

[2] Diversity of macrociliary size, tooth patterns, and distribution in Beroe (Ctenophora)

[3] Photo from

Categories: Uncategorized

6 replies

  1. How long does it take for a Beroe to digest a jelly so much bigger than itself? Can it just keep expanding bigger and bigger?!

    • I’ve never had the opportunity to time digestion in Beroe, but I imagine it’s pretty fast. They can really expand their bodies. Once on a research trip we spotted a jellyfish that was pulsing and pulsing but not going anywhere. We got really close before noticing that it was entirely inside a Beroe, which was so stretched out it was almost clear.

  2. Interesting post as usual :).
    Is it really as quick an ingestion as the videos show? or are they speeded up? We had a Beroe in the lab a month or so back and while we didn’t have any nice jellies to feed it, the Beroe seemed really chilled and was not really reacting to any of the plankton we offered it. I managed to put a pteropod inside the mouth which stayed for an hour or so, flapping away, before being spat out again.. Respiration was also sloooooow compared to something like a scyphozoan, but I guess increases considerably if they are hunting seriously.

  3. Hi my loved one! I wish to say that this article is awesome, fantastic written and include approximately all important infos. I’d like to peer extra posts like this.


  1. Jellies, jellies everywhere! |

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s


Get every new post delivered to your Inbox.

Join 438 other followers

%d bloggers like this: