Spaceships in the Ocean

Our ocean holds secrets: the strangest alien forms, reminiscent of spaceships.  These gelatinous creatures are luminous, spreading waves of colour through their unpigmented body.  They are the ctenophores, or comb jellies, and are our latest discovery of the magical organisms that lurk under our hulls.

Anatomy of a Comb Jellyfish

They are small (a few millimeters to several centimeters) and nearly totally transparent, which makes them relatively inconspicuous in day time, but at night, when you shine a strobe on them they glow. They occur in marine habitat both inshore and offshore, and from near the surface to the deep ocean. They are not uncommon, yet we know little about them.


Anatomy of a Ctenophore Bolinopsis

The Ctenophore does not look like a traditional jellyfish since it does not have a bell and trailing tentacles.  Instead it has translucent and highly expandable lobes and ladder-like structures – the combs.  It swims by the synchronous beating of eight comb rows that are made of thousands of fused cilia, and through the flapping motion of the lobes. Ctenophores are strikingly beautiful, with shimmering waves of rainbow colours produced by the diffraction of light passing through the cilia as they flutter like eyelashes. They are also bioluminescent, glowing blue in the dark.

Another distinguishing feature is that the comb jellies lack stinging cells and have developed other strategies such as sticky tentacles and oral lobes to capture prey, much like spider webs.  They won’t hurt you but they are carnivorous.  You can see their digestive canals glowing in the centre.  They prey on zoo plankton: copepods (tiny crustaceans), invertebrates, larvae and fish eggs.  And they fall prey themselves to a variety of creatures seeking easily digested gelatinous morsels, including other jellies, fishes and sea turtles.

Ctenophore bolinopsis

Light diffraction along the comb rows – photo taken in daylight

One of many kinds

There are apparently over a hundred different species of Ctenophores.  The scientists at Jellywatch confirmed the identification of the ones we observed as the Ctenophore Bolinopsis. These aggregated in Sealers Cove, a large bay open to the ocean at Wilsons Promontory, on a full moon night.  They were drifting with the tide past our anchored boat.  We would have seen maybe 40 to 60 of them around us, but there could well have been hundreds in the bay.  The next day we moved to Little Waterloo Bay and were ready for another light show, but none were there.  It might have been a blessing, as although these creatures are very beautiful, there are fears they might become a pest, like their cousins the Mnemiopsis which invaded the Black Sea and have spread into the Mediterranean sea.

Like Spaceships in the Cosmos

The photos we took on the first night show how bizarre and fascinating these “alien spaceships” are. To us they look like spaceships in the Milky Way. On one hand we are excited to have seen these spectacular comb jellies, but on the other we wonder whether they are another sign of ecological trouble ahead.

Take a look at this gallery; isn’t nature astounding? All photos were taken with the Olympus TG4 waterproof camera, from the bottom step of the sugar scoops on our boat.  I was precariously kneeling head down, bottom up, with a torch in one hand and the camera in the other, and my arm in the water up to my elbow! No diving in the very chilly water that night, but pleasing results nevertheless. All but the last photo in the gallery were taken at night.

34 thoughts on “Spaceships in the Ocean

  1. These are truly wondrous creatures. At the nearby Monterey Bay Aquarium, the jelly-fish display is one of the most highly-lauded. They back light them and, like you say, its just out-of-this-world. Not sure if they are showing comb jellies. Thanks for the fascinating post.

    • You are very welcome Craig – the Jelly Watch organisation is based in Monterey and have been really helpful. Keep your eye out for the next jelly post in 2 weeks… More spectacular shots!

  2. Wow amazing creatures, I never knew such aliens existed, there is so much to learn, let’s hope we do not totally destroy our planet.

  3. Wow! Those are awesome images!! I’m so envious you saw these in the wild! We spent probably an hour marveling at a tank of them at the Monterey Bay Aquarium – such incredible creatures!

  4. I can only reiterate the ‘WoW’! What wonderful photos…The only obvious jellyfish I’ve seen around the top of the Whitsunday’s are the big orange globulous invasive types… but then again that was during the day and, as we are in croc country, I will not be head down, bum up suspended in the water (day or night!). We look forward to your next posts. Cheers Trish

    • Thanks Trish – can’t say we are looking forward to having to watch for crocs when we get up north! Definitely no playing in the water especially from dusk onwards… Crocs and sharks’ favourite hunting time!

  5. Fascinating!! I love posts like this because I really love science. How special it would be to see these creatures in the water and even more special that you shared them with us. Thank you so much for the images and information. Loved it!

  6. I’ve loved all your underwater (or in this case partially underwater) images!! This is such a wonderful creature. I don’t think I will get to see anything quite like this off the coast of Kos but I was so impressed with the clarity of the images you have shared with us that I made a sneaky purchase of a TG4 to take out with me this year 😀 Very excited now!!

      • I have tried underwater photography a few times before with different bits of kit. I had an aquapac casing for my dlsr but found that unless you have a lens mounted that’s an almost exact fit to the space given it becomes increasingly difficult to focus. Also it was impossible to view the lcd. Just altogether unwieldy and frustrating! Then I got a little Sony compact with an underwater housing that was affordable. Good video but again I had issues focusing for stills and also found that fringing and chromatic aberration was dreadful at times! Again, the housing itself was pretty unwieldy. I’ve found it really easy to suss out all the functions and features of the Olympus already 🙂 Although some of the function buttons are quite small I don’t think I’ll have a problem adjusting any of the settings underwater. It’s got a good weight to it too! I like the choice of having RAW but must say that I’m a bit disappointed to find that if I choose that I can’t go to High Speed shooting. I also noticed that there are quite a number of add on accessories for the camera. Won’t get anything else this year but great option for the future! Best of all I got a trade in on my old kit. Not a huge amount but every little helps 🙂

      • Yes with the add-ons I have the fisheye lens and the flash diffuser. I found the fisheye wet lens sometimes gives a weird distortion if you angle the camera, so not convinced it is that great. The diffuser helps with backscatter. Looking forward to seeing your shots!

      • Yes I think a diffuser would be handy!! I would really like a proper underwater torch/light but they’re really really expensive. I like looking for octopus in the crevices of rocks and flash just doesn’t quite cut it! I am thinking of improving with a led spotlight in a waterproof casing for a smartphone. We shall see how I get on 😉

  7. Pingback: Solitary Explorations | Sv-Anui

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