Another Notaeolidia from Antarctica

March 14, 2007
From: David Cothran

Hi Bill,

Here is another recent photo of a Notaeolidia. I took this one to be N. gigas, as it strongly resembles Norbert Wu's upper photo of that species [message #19612]. To me it looks significantly different from the ones I photographed at Elephant Island [message #19425 ], though I am certainly no expert on this taxa. Note the smooth rhinophores and longer cerrata that more completely conceal the dorsal surface. On the other hand, now that I look again, Norbert's lower photo looks more like the one in my first message, so now I'm confused. Seems like a lot of variation for a single species, though I know that nudis can be that way - and I do appreciate that it would require a genital dissection to be sure. I have seen both these types a number of times around the Antarctic Peninisula and the South Shetlands, and I think of them as quite distinct since I have not seen anything I would call an intermediate form.

What do you think? I have some more photos of this species/type from this location on another date, if you would like to see them.

Locality: Neptune's Bellows, Deception Island, South Shetland Islands, Southern Ocean. 27 meters. Length 7cm. 1 February 2007. Rock wall
David Cothran

Best regards,

Cothran, D.B., 2007 (Mar 14) Another Notaeolidia from Antarctica. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Dear David,
This animal does look very like Norbert Wu's photo. I must say I was a little hesitant about the identity of his photos, as the cerata are in distinct transverse rows, the rhinophores are very long, and the edge of the mantle doesn't show the characteristic waves that species of Notaeolidia are supposed to have. Your earlier photos from Elephant Is [message #19425] seem to be a much 'better' fit for Notaeolidia gigas. Which leaves us with the question - is Norbert Wu's animal, and the one in your photo here, N. gigas or something else?

As I have said in your other message [#19538] we really need to look at the anatomy before we can be sure. In many ways this is an unknown fauna that your are sampling. Have a look at Michael Schroedl's comments [#19656] on Nobert Wu's species.

At the moment I will leave it with Notaeolidia gigas but I am sure it is not that species.

Best wishes,
Bill Rudman

Rudman, W.B., 2007 (Mar 14). Comment on Another Notaeolidia from Antarctica by David Cothran. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

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