Noumea norba
Marcus & Marcus, 1970
Order: NUDIBRANCHIA
Suborder: DORIDINA
Superfamily: EUDORIDOIDEA
Family: Chromodorididae
DISTRIBUTION
Widespread in tropical Indo-West Pacific
PHOTO
Split Solitary Is, Coffs Harbour, northern New South Wales, December 1990. Lower photo showing two animals on sponge with eggs, 70ft (approx 24m), PHOTOS: C. Buchanan.
In Noumea norba the background colour of the mantle can vary from reddish purple to pinkish orange in different specimens. There is a broad milky yellow or creamy white band around the mantle edge and on the inside edge of this band are a series of reddish purple streaks or smudged marks. In the midline there is a broad band of irregular width of the same colour as the mantle border. This band always encircle the gill pocket and can be broken in two about half way along its length. The gills and rhinophores are tinged with orange-red. Noumea norba and Noumea varians are quite similar in colour however their internal anatomy is quite different. One way of distinguishing living animals is that N. norba is quite like a species of Chromodoris in shape with a relatively wide flattened body and broad mantle skirt while N. varians is more like a Hypselodoris with a relatively high body and narrow mantle skirt.
In an earlier revision (Rudman, 1986) I considered this species to be a synonym of Noumea purpurea but now that we no more about the anatomy and colour variation in that species, they are clearly distinct.
See the Noumea purpurea Colour Group Page to compare this species with others of similar colour.
Reference:
•Rudman, W.B. (1986) The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: Noumea purpurea and Chromodoris decora colour groups. Zoological Journal of the Linnean Society 86(4): 309-353.
Rudman, W.B., 1999 (December 5) Noumea norba Marcus & Marcus, 1970. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/noumnorb
Related messages
Noumea norba from Indonesia?
November 14, 2005
From: Bill Van Antwerp
Bill:
We found this guy in Indonesia (Rinca) and I think it is a Noumea norba but it isn't supposed to be there.
Locality: Rinca, INdonesia. Depth: 40 ft (?). Length: 15 mm. Photographer: Bill Van Antwerp
Can you help
thanks
Bill Van Antwerp
bill.van-antwerp@medtronic.com
Van Antwerp, W., 2005 (Nov 14) Noumea norba from Indonesia?. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/15262Dear Bill,
I am not sure why you think Noumea norba is not supposed to be in Indonesia. I note I haven't included a geographic distribution on the Fact Sheet, but just from the messages on the Forum we can see it has a wide distribution in the tropical Pacific and Indian Oceans, so we would expect it to be found in Indonesia. I'll add a note on the Fact Sheet
Best wishes,
Bill Rudman
Noumea norba from South Africa
July 6, 2005
From: Colin Ogden
Hi Bill,
Another new nudi for me. I cant find it in my books. Could it be a Noumea?
Locality: Sodwana Bay, South Africa, Indian Ocean. Depth: 30 metres. Length: 15 mm.28 June 2005. Reef. Photographer: Colin Ogden
Thanks a ton
Colin
scubaco@iafrica.com
Ogden C M, 2005 (Jul 6) Noumea norba from South Africa. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/14151
Dear Colin,
I am pretty sure this is Noumea norba but it is possibly N. varians. The mantle seems narrower than in N. norba, but not as pronounced as in N. varians, so that is by best guess. I found out several years ago that the only sure way to identify some of this Noumea purpurea group of species was to dissect them - which is not always practical, or ecologically sustainable!.
Best wishes,
Bill Rudman
Noumea norba and Hypselodoris bullocki
April 20, 2005
From: Bruce Potter
Dear Bill,
I was preparing to film this Hypselodoris bullocki, when along came the Noumea norba, and no I did not have to move them - the N. norba just came right on by as I was fiming the H. bullocki. This was on a coral and rubble site on the outskirts of Honiara, Solomon Islands. It was at about 8 meters.
Locality: Honiara, Solomon Islands, Pacific Ocean. Depth: 8 meters. Length: 12 mm. 7 January 2005. Coral Rubble Sand. Photographer: Bruce Potter
Regards
Bruce.
bandppotter@bigpond.com.au
Potter, B., 2005 (Apr 20) Noumea norba and Hypselodoris bullocki. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/13525Dear Bruce,
They make a spectacular pair
Best wishes,
Bill Rudman
Noumea norba from Reunion Island
February 12, 2005
From: Philibert Bidgrain
Dear Bill,
Reunion Island sea slugs.
We have only one specimen, of this species which seems to be a specimen of Noumea norba
Locality: "Cap la Houssaye" at Saint Paul, Reunion Island, Indian Ocean, Depth: 15 m. 24 March 1985. Photographer: Maurice Jay
Best Regards
Philibert Bidgrain
http://vieoceane.free.fr/runseaslug/indexslug.htm
pbidgrain@yahoo.fr
Bidgrain, P., 2005 (Feb 12) Noumea norba from Reunion Island. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/13114Dear Philibert,
Yes this is Noumea norba.
Best wishes,
Bill Rudman
Noumea norba from the Philippines
December 14, 2002
From: Erwin Köhler
Dear Bill,
Here are more pictures from Georg Heinze [Georg.Heinze@t-online.de] from the Philippines, Negros Oriental Island, "El Dorado" housereef
Size: 15mm
Depth: 15m
Date: May 2002
Is it Noumea varians?
Erwin
Erwin@medslugs.de
Dear Erwin,
Unfortunately there is no perfect way identifying this group of chromdorids externally. I am 99% sure that these are Noumea norba. certainly the colour of the gills, and the reddish-purple spotting along the inside edge of the mantle margin, are typical of that species.
Best wishes,
Bill Rudman
Noumea alboannulata? from the Red Sea
April 10, 2002
From: Dr Jacob Dafni
Dear Dr. Rudman,
Being the author, you may enjoy knowing that this small slug, which I collected and pictured in the late 80's, in Eilat, Red Sea, is to the best of my knowledge Noumea alboannulata Rudman, 1986.
Jacob Dafni
jdafni@netvision.net.il
Dafni, J., 2002 (Apr 10) Noumea alboannulata? from the Red Sea. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/6693Dear Jacob,
As you will see on the Noumea purpurea colour-group Page there are quite a few species which are difficult to separate externally. I think your animal is Noumea norba which I thought in 1986 was a colour forn of Noumea purpurea. It is in fact through all the extra information that interested people like you have sent to the Forum that we are able to sort out some of these problems, and in some cases become aware of them.
In Noumea alboannulata the white median line always splits into an elongate circle around the gill pocket. In Noumea norba the median white line is either a thick continuous band or breaks aup into two or three elongate patches.
Best wishes,
Bill Rudman
Nudibranch from Bremer Bay, Western Australia
December 8, 2001
From: Craig Lebens
Dear Bill
Found this recently and can't identify it in any of my books. Any ideas as I've never seen it down here on the south coast although we have been seeing lots of things down here the last 12 months that shouldn't be down here.
[Bremer Bay, south west corner of Western Australia, 7 meters.
Keep blowing bubbles
Craig Lebens
lebdive@comswest.net.au
Lebens, C., 2001 (Dec 8) Nudibranch from Bremer Bay, Western Australia. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/5776Dear Craig,
I am pretty sure this is Noumea norba but this is one of a group of similarly coloured species that sometimes need to be checked anatomically to be sure of their identity. See the Noumea purpurea Colour Group Page to compare this species with others of similar colour. The other posssibility is Noumea varians but that species has a very narrow mantle skirt and I think from your photos that the skirt is reasonably wide in your animal.
Best wishes,
Bill Rudman
Re: Noumea norba from Hachijo Is, Japan
August 14, 2001
From: Nishina Masayoshi
Dear Dr.Rudman,
Regarding your question - I guess it's coralline alga. Please take a look at attached image.
Best regards,
Nishina Masayoshi
nishina@hpe15.wips.co.jp
Nishina, M., 2001 (Aug 14) Re: Noumea norba from Hachijo Is, Japan. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/5074Thanks Nishina,
Ceratainly looks like a coralline alga. I had hoped it might be a possible food sponge.
Best wishes,
Bill Rudman
Noumea norba from Hachijo Is, Japan
August 12, 2001
From: Nishina Masayoshi
Dear Dr Rudman,
Noumea norba? is rather say rare at Hachijo and Sagami Bay.
Date: 29 June, 2001
Place: Sokodo, Hachijo Island, Japan
Depth: 10m
Size: 10mm
Photos by Nishina Masayoshi
Best Regards,
Nishina Masayoshi
nishina@hpe15.wips.co.jp
Nishina, M., 2001 (Aug 12) Noumea norba from Hachijo Is, Japan. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/4978Thanks Nishina,
Is the pink background colour an encrusting coralline alga, or is it a sponge?
Best wishes,
Bill Rudman.
Tonga Records: Noumea norba
May 29, 2001
From: Don Barclay
Here is another from Utungake Island, Vava'u, Tonga in February of 2001. The photos of this little Noumea norba are all blurry, mostly because my camera wouldn't focus on him. He was less than 5mm long, but showed typical coloring for the species except for some purple dots on the anterior edge of the mantle.
Don Barclay
n5ols@samoatelco.com
Barclay, D., 2001 (May 29) Tonga Records: Noumea norba. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/4418Thanks Don,
Another useful record.
Bill Rudman
Noumea norba from Solomon Ids
January 8, 2001
From: Bruce Potter
Dear Bill,
I found this very small nudi last sunday. It would have been about 12-15 mm long. Possibly only a juvenile.
Would I be correct in identifying it as Noumea norba?
It was at about 14 meters on a coral and rubble site, just out of Honiara, Solomon Islands.
Regards
Bruce Potter.
bruce.potter@adventist.org.sb
Potter, B., 2001 (Jan 8) Noumea norba from Solomon Ids. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/3390Dear Bruce,
Yes this is Noumea norba. Usually the median line is broken but not always. Have a look at the page on the N. purpurea colour group to see similarly colored species.
Bill Rudman.
Noumea norba? from Hawaii
December 21, 1999
From: Anne Dupont
Hi Bill,
I was trying to identify some Hawaiian nudibranchs and Mike Miller of the Slug
site was helping me. I sent Mike this photo and he said that my animal appears to be Thorunna gloriosa. Mike said that he did some further research and found that the identification of Thoruuna gloriosa in Han's book was changed to Noumea purpurea at a later date! He referred me to your site discussion on Noumea purpurea and the N. purpurea Colour Group.
According to your posting, the known distribution is limited to Japan. I
photographed this critter in Hawaii several years ago and unfortunately this is the only (poor) photo I have. I thought you might be interested in it.
Happy Holidays,
Anne
adupont@gate.net
Dupont, A., 1999 (Dec 21) Noumea norba? from Hawaii. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/1700Dear Anne,
It is in an interesting photo. This species was identified by Bertsch & Johnson (1981) Hawaiian Nudibranchs as Thorunna gloriosa [p60 - top photo only], but it is not Bergh's C. gloriosa [which = Noumea varians]. At that time I identified this Hawaiian form as Noumea purpurea. On the basis of a lot more information now available, including great photos people are sending to the Forum, in a recent message I revised my opinion and now consider that Noumea purpurea and Noumea norba are quite distinct. I think the Hawaiian animal is a colour form of Noumea norba, although the unbroken white median line suggests it is possibly a distinct and unnamed species.
So you can blame me for the confusion. Hopefully they are easier to identify now, but the similarity in colour between some species means that a look at the anatomy may be the only way to be sure.
Bill Rudman.
Reference:
•Rudman, W.B. (1986) The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: Noumea purpurea and Chromodoris decora colour groups. Zoological Journal of the Linnean Society 86(4): 309-353.
