Notaeolidia gigas??
Order: NUDIBRANCHIA
Suborder: AEOLIDINA
DISTRIBUTION
Antarctic waters
PHOTO
Locality: Neptune's Bellows, Deception Island, South Shetland Islands, Southern Ocean. 27 meters. Length 7cm. 1 February 2007. Rock wall
David Cothran
I doubt if this aeolid is identifiable without an anatomical study. It has previously been misidentified on the Forum as Notaeolidia gigas [see upper photo in Norbert Wu's message #19612]. See further comment and messages below. It is clearly not a species of Notaeolidia.
Authorship detailsRudman, W.B., 2007 (March 15) Notaeolidia gigas?? [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/notagiga02
Related messages
Aeolid from King George Island, Antarctica
March 16, 2007
From: Bill Rudman
In a recent message [#19656], Michael Schroedl mentioned Dirk Schories' website with nudibranch photos from King George Island, Antarctica.
One animal illustrated is the species in David Cothran's message [#19540] and which has been identified as Notaeolidia gigas by Norbert Wu [#19612]. When I saw Dirk's photos they clealry show that this is not a species of Notaeolidia. Dirk has kindly allowed me to post his photos on the Forum.
What these photos show is that the cerata are arranged in distinct transverse rows on each side of the body, with up to five cerata in each row, Compare this with photos of Notaeolidia gigas [message #19679] in which there is a distinct mantle 'skirt' and the cerata, arranged in irregular rows, are confined inside the 'skirt'. One other clear distinction is the very long smooth rhinophores in this species, quite different from the shorter wrinkled rhinophores in all photos of Notaeolidia I have seen. There also seems to be a tentacular anterior foot corner [propodial tentacle] in this aeolid, like the one in Flabellina falklandica [message #19656 ].
Locality: Napier Rock, Admiralty Bay, King George Island, Antarctica. Upper photo: 08 February 2003. Lower photos: 12 February 2003. Photos: Dirk Schories. [ http://www.guiamarina.com/antarctica/ ]
I doubt if this aeolid is identifiable without an anatomical study. Looking at Norbert Wu's photos it seems the upper photo is this unidentified species, and the lower photo is Notaeolidia gigas [#19612]. I will change the photos on the Fact Sheet to stop further confusion. Despite being unable to name this species, it is nice to be able to resolve the confusion.
Best wishes
Bill Rudman
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,
David
david@wandering-eye.com
Cothran, D.B., 2007 (Mar 14) Another Notaeolidia from Antarctica. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/19540
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
