Gorgeous sea slugs from southeast Asia

Reader Brian called my attention to a beautiful collection of sea slugs (nudibranchs, or shell-less marine gastropods) at EarthTouch News Network. It’s likely, but not certain, that the striking appearance of many species, as you see here,  are aposematic: they advertise the fact that they’re toxic, distasteful, or dangerous (stinging cells) with their easily-recognized patterns and colors.

These marine jewels all come from one small area. As the site notes:

Take a dive in the waters surrounding Pulau Hantu, a small island off the west coast of Singapore, and you may reemerge feeling unimpressed. Visibility around the island rarely tops three to four metres, and plentiful algae tints the water a vivid green. For macro photographers like Katherine Lu, however, Hantu is a hidden gem. The island harbours a little-known reef that’s teeming with tiny marine life – and among its most remarkable inhabitants are the local sea slugs.

All photos are by Lu; captions are from the website:

A nudibranch in the genus Stilliger. Image: Katherine Lu/WetPixel


Bornella anguilla. Image: Katherine Lu/WetPixel


Sakuraeolis kirembosa. Image: Katherine Lu/WetPixel

This little creature can photosynthesize in its body:

“Shaun the sheep” Costasiella sp. Measuring just two to three millimetres, this tiny sea slug has the ability to absorb chloroplasts from the algae it feeds on. This allows photosynthesis to occur in the animal’s body. Image: Katherine Lu/WetPixel

For more of Lu’s fantastic photography, go here.




  1. GBJames
    Posted February 21, 2018 at 2:54 pm | Permalink

    Cute little buggers. They look good enough to eat!

    … wait…

    • Posted February 21, 2018 at 3:53 pm | Permalink

      I saw the headline in my RSS feed without the pictures and my first thought was that the article would be about yummy to eat sea slugs.

  2. busterggi
    Posted February 21, 2018 at 2:54 pm | Permalink

    if only their land cousins could be as pretty.

  3. Posted February 21, 2018 at 2:57 pm | Permalink

    Reblogged this on The Logical Place.

  4. Posted February 21, 2018 at 3:01 pm | Permalink

    “Shaun the sheep” fantastic adaptation!
    Amazing display of colour and form from these little creatures… thanks.

  5. glen1davidson
    Posted February 21, 2018 at 3:13 pm | Permalink

    “Shaun the sheep” Costasiella sp.

    Sheep face, pasture body.

    Descriptive term for its chloroplasts–“kleptoplasts.”

    Glen Davidson

  6. Paul S
    Posted February 21, 2018 at 3:13 pm | Permalink

    Beautiful. 3-4 meter visibility can be some of the best dives. That’s about all you get in some lake Michigan wreck dives and you’ll find many tiny life forms if you stop to look.

    • rickflick
      Posted February 21, 2018 at 7:09 pm | Permalink

      Credit the invasive Zebra Muscles. They filter out the cloudy plankton so your camera can get a good grip on your prey. When I lived near Lake Michigan in the 1960s, visibility was about 6 – 10 feet.

      • Paul S
        Posted February 21, 2018 at 7:29 pm | Permalink

        Quite right. Zebra muscles and Asian carp are wreaking havoc on ecosystems from the Mississippi into the Great Lakes. I’ve cut myself more than once on the little buggers cleaning debris in Burnham Harbor.

  7. Posted February 21, 2018 at 3:17 pm | Permalink

    Wow, did not know they could be so pretty!

  8. BobTerrace
    Posted February 21, 2018 at 3:28 pm | Permalink

    Natures beauty is unsurpassed.

  9. Christopher
    Posted February 21, 2018 at 4:12 pm | Permalink

    Now that’s the kind of nudi beach I wanna go visit!

    I really love that B. anguilla! It looks perfectly adapted for camouflage in a 1970’s living room.

  10. Barry Lyons
    Posted February 21, 2018 at 4:39 pm | Permalink

    One doesn’t normally see “gorgeous” and “sea slug” together, but this is indeed an excellent (and gorgeous) exception.

    • René
      Posted February 22, 2018 at 8:43 am | Permalink

      Don’t think so, just google “sea slug”

  11. Genghis
    Posted February 21, 2018 at 4:40 pm | Permalink


  12. Posted February 21, 2018 at 4:54 pm | Permalink

    Are there any ideas on the adaptive significance of so much color?

    • eric
      Posted February 21, 2018 at 8:19 pm | Permalink

      Well the last one is explained – it makes energy/food.

      The other ones? Not sure. Probably more than one reason. Some may be “don’t eat me – poison” while others may need the light if the water is murky. Heck, if they’re in a little lagoon with few predators, it could even be some sort of reproductive display.

  13. tony in san diego
    Posted February 21, 2018 at 5:14 pm | Permalink

    clearly evidence of Intelligent Design

  14. Mark R.
    Posted February 21, 2018 at 5:46 pm | Permalink

    Beautiful little buggers. 2-3mm? How did she even see Shaun the sheep?

  15. Andrea Kenner
    Posted February 22, 2018 at 5:31 am | Permalink

    One word: Wow!

  16. Posted February 22, 2018 at 5:45 am | Permalink

    They’re gorgeous. I like the second one the most. The last one looks like it has a white Pikachu face.

  17. Posted February 22, 2018 at 11:38 am | Permalink

    The last one would have confused – and fascinated – the world’s first marine biologist (Aristotle) as it would certainly get even closer to (what he took to be) the plant-animal corner cases he had trouble with.

    • Posted March 3, 2018 at 3:11 pm | Permalink

      To me, they all resemble beautiful flowers.

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