Glaucilla bottles eater in a green bucket

Random visit


Thanks to SFKelly for pointing me to nudibranches.



"Glaucilla marginata. This aeolid nudibranch, and its close relative Glaucus atlanticus, are beautifully adapted for their life of floating upside down in the sea, feeding on the 'bluebottle' or 'Portugese man o' war', Physalia. They store the most powerful of the bluebottle's stinging cells at the tips of their slender cerata (20mm)"


From the "seaslugforum: "The cerata of

Glaucus atlanticus (Fig. 5) are arranged in a single row in each arch while Glaucilla marginata (Fig. 6) they are in multiple rows." So this must be Glaucilla marginata?


From the wikipedia site: "Glaucus atlanticus is a nudibranch of the family Glaucidae, the only member of the genus Glaucus. It is 4cm long. The slug is distributed throughout the world's oceans in temperate and tropical waters. G. atlanticus preys on the Portuguese Man o' War, Physalia physalis, Velella velella, the Blue Button, Porpita porpita, and the violet snail, Janthina janthina.


With the aid of a gas-filled sac that is located in its stomach, G. atlanticus is able to stay afloat at the surface. Due to the location of the gas sac the blue sea slug actually floats upside down. The dorsal surface, actually the foot and underside, is either a blue or blue-white coloration. The true dorsal surface is completely silver-grey. This coloration is an example of counter-shading, which helps protect G. atlanticus from predators from both below and above.


G. atlanticus is able to feed on P. physalis due to its immunity to the venomous nematocysts. The blue sea slug will consume the entire organism. After consumption it will select the most venomous nematocysts and use them as a defense."


A kid was collecting plenty of those "fishes" at Honey moon bay, I shot them in his (green) bucket, they were about 10-20 mm large. They were not very reactive; folding in a ball seemed to be their most extreme reaction. Sea creatures were very blue there that day (those, blue bottles and some others).


Note: as many, I recently went to see "Varekai" by cirque du soleil...and was a bit frustrated by not being allowed to take pictures...but a guess: this (or similar) may have been a source of inspiration for the great costume designer Eiko Ishioka.


Un enfant ramassait plein de ces "poissons" a Honey moon bay, je les ai photographies dans son seau (vert), ils mesuraient environ 10-20 mm. Tres passifs, leur principale defense semblait etre de ce plier en boule. Ce jour la, les petites creatures de l'ocean etaient toutes bleues (ceux-ci, les blue bottles , et d'autres)


Another great link on the cousin Glaucus atlanticus

  • Andrew Purdam PRO 8y


    I much prefer this "natural" shot of it. It is strange enough.
  • Pierre Pouliquin PRO 8y

    :) amazing stuff hey!?
  • David Cosgrove 8y

    Very cool creature - and interesting commentary...
  • Pierre Pouliquin PRO 8y

    Thx for your visit and com
  • Pure_Ignorance 8y

    Trippy looking things eh?

    I've just spent the last hour finding out what the hell these are after finding one down the beach.

    Thanks for the sweeet pic, But my kid'll be dissapointed to find out it's not an alien fish like he thought... or is it?
  • Pierre Pouliquin PRO 8y

    Pure_Ignorance :) surprising indeed. Oh...putting a name on them...doesn't say ...for sure...where they come from, no? Lots of ocean creatures might look quite alien....
  • Hafizi Fazli 7y

    cute...look like a alien's spaceship..
  • mynameisdan 7y

    Instantly striking... I had to have a closer look!
  • Lisi Cai 7y

    Wow, I have never seen anything like this. Truely something amazing!
  • *amy&kimball PRO 7y

    amazing nudibranch! looks like a crystal
  • Nuytsia@Tas PRO 7y

    Hi, I'm an admin for a group called Australian Marine Life, and we'd love to have this added to the group!
  • Anthony Thomas 7y

    Hi, I'm an admin for a group called NaturePhotographs *Post 1, comment on 2*, and we'd love to have this added to the group!
  • heycarrieann331 PRO 7y

  • Jakub Hlavaty 7y

    Wow! Like from a science fiction movie :-)
  • Jeff Bauche 7y

  • Jonathan PRO 7y

    Hi, I'm an admin for a group called Flickr's Best Creatures, and we'd love to have this added to the group!

    Since our group is new, please consider adding more your wonderful creature shots!
  • paulhypnos PRO 5y

    These are really amazing. I found this one floating in a rockpool after a storm.

    Glaucus atlanticus  -  Blue Dragon   mDSCN4127b
  • paulhypnos PRO 5y

    The Glaucilla marginata and Glaucus atlanticus are often confused. This photo shows the Glaucus atlanticus on the left and the Glaucilla marginata on the right of the photograph. The obvious distinguishing feature is that the cerata on the Glaucus atlanticus all come out in one plane. With the Glaucilla marginata the cerata come out in all directions.
    Click on photo below for more detail.

    Glaucus atlanticus and Glaucilla marginata  - AUSTRALIA 1 DSCN4137 copy
  • Martin LaBar PRO 4y

    Ah. A Nudibranch photo. I'm adding this to a gallery of photos of marine life, and may use it in other ways, approved by the photographer. Thanks!
  • Martin LaBar PRO 4y

    I have now used this photo in creating a Flickr graphic, attempting to illustrate marine biodiversity. That graphic is here:
    Nudibranchs: biodiversity, Psalm 104 by Martin LaBar (going on hiatus)
64 faves
Taken on April 9, 2007
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  • 10.9 mm
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