Some time ago Kimberlee, who is the woman behind a blog from the far north of Alaska called The Buggy Side of the Dog, posted a video of a jellyfish that produced an amazing light show along rows of cilia. While on first blush these multicolour lights along the eight rows of cilia would appear to be a form of bioluminescence they are not. What is actually happening is light is being scattered by the cilia as they pulse along the row, sort of like a multitude of tiny prisms doing the wave.
The jellyfish is a beroid ctenophore, one of the comb jellys, and while they do, in fact produce bioluminescence it can only been seen in the dark. The beroids are predators, using a cavernous mouth to engulf their prey, which is almost exclusively other comb jellyfish.
Yesterday I had a couple of hours to kill while Travis was in school for the afternoon. Alright, I didn't really have any hours to kill, but decided to kill a couple instead of any of my chores or other responsibilities. Hilary and I headed over to Victor Bay, unsuccessfully looking for the ukpikjuaq (Snowy Owl) on the way. It was almost dead calm over there, and we sat in the sun on some rocks by the shore, drank some coffee (well I did) and waited for something interesting to pass our way.
Well something did, for I first noticed one, and then dozens of these gelatinous predators in the water. Most were small, around a centimetre in length, but some (including the first one I noticed) were larger, four centimetres. We watched them drift/swim around for awhile, catching glimpses of their light show, usually when they were closest to the surface. Eventually we caught a couple of them and brought one back home to photograph, as all my attempts to get a decent photo in the field failed miserably. The photos are below, and in the first one you can see just a bit of the light show (a couple of cilia are blue) but it really doesn't do it justice.
Oh, one quick story before the photos. I was pointing out the first jellyfish to Hilary when she asked "Where are the turtles?". When I explained to her that there were no sea turtles up here, she replied "But turtles eat jellyfish". What? I mean they do, but where does a three year old learn that? I suspect Go Diego, Go.
Comments
5 responses
I’d love to see those jellyfish. One of my favourite arctic memories from a summer trip in 1989 is sitting on rocks besides the sea near Norway’s North Cape and watch beluga whales swim underwater as white shadows. I am sure jellyfish with a bling are a good match to that.
They are apparently very widespread in all the world’s oceans, so you could find yourself with the opportunity sometime soon. I’ve had the opportunity to see narwhal swim by while sitting on the same rocks as where we found the jellyfish. It is an impressive sight.
All the jellyfish I saw (alive in the water or dead on the beach) in the Baltic, North Sea or Mediterranean simply looked like transparent pudding, no iridescense of any kind. Maybe they are more common in Arctic waters?
What is your black backdrop in the photos?
Hi Bonnie,
The backdrop is a black t-shirt.