Northwest Dive Club

Today, we were diving in Hood Canal, and the water was full of jellies. In particular, there were a whole bunch of large ones which appear similar to this, and I assume are a Beroe species: http://davidwrobel.zenfolio.com/p809276 ... #h398b7cca

What was cool, and totally new to me, was that they were FEEDING. And if anyone has not seen this, it's fascinating. The more pointed end of the jelly is a flat "mouth", and when they feed, it suddenly assumes a round shape, and the jelly elongated violently, sucking plankton in I assume by simple hydrostatics. I watched numerous individuals doing this today, and I was mesmerized. So the next time you're sitting around in midwater with these guys, spend some time watching them. It's pretty cool! I wish Peter had gotten the action on video, but he didn't.

Very cool.

I noticed several of these comb jellies during the recent club dive at Sund Rock, and tried to get a decent pic or two - mostly without success. While I didn't get to witness them actively feeding, one of my pics appeared to show a sea gooseberry jelly inside one of them. A case of a successful predation, or accidental ingestion?

Yes, you have a picture of the "butt" end -- the other end is the mouth. The transformation of the animal from floating to feeding shape is extremely rapid and very violent, and truly amazing. I spent some time watching them, trying to figure out what was triggering the change, but I couldn't identify anything. They must chemosense some kind of prey, but it was far from obvious.