Noumea varians
(Pease, 1871)
Order: NUDIBRANCHIA
Suborder: DORIDINA
Superfamily: EUDORIDOIDEA
Family: Chromodorididae
DISTRIBUTION
Tropical western Pacific and Indonesia.
PHOTO
UPPER: Christmas Island, Indian Ocean, 12mm long alive, may, 1981. PHOTO: John Hicks.
LOWER: Broadhurst Reef, Townsville, Queensland, October 1975, 9mm long preserved. PHOTO: Ian Loch.
The mantle of Noumea varians is translucent with the pink or orange of the underlying viscera showing through. Often their is a tinge of purple in the mantle colouration. Around the edge is a broad creamy-orange band, and on its inside edge is a thin reddish purple line which anteriorly and posteriorly breaks into a series of red-purple patches. Down the dorsal midline is traces of a broken white line. The rhinophore club is translucent orange with an opaque white core. The gills are translucent clear with a tinge of orange in the upper half.
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.
See the Noumea purpurea Colour Group Page to compare this species with others of similar colour.
Reference:
•Rudman,WB (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 (November 5) Noumea varians (Pease, 1871). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/noumvari
Related messages
Noumea varians from Reunion Island
February 27, 2009
From: Sully Bachel
Hello Bill
Here is a Noumea varians moving on a sandy rock at cap La Houssaye, Réunion Island.
Locality: Cap la Houssaye, 9 m, Reunion Island, Indian Ocean, 22 November 2008. Length: 12 mm. Photographer: Sully Bachel.
Best regards
Sully Bachel
http://seaslugs.free.fr/index.htm
s.bachel@orange.fr
Bachel, S., 2009 (Feb 27) Noumea varians from Reunion Island. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/22257
Dear Sully,
Thanks for this photo which arrived fortuitously at the same time as Barbara Hanchard's photos [message #22276] of animal almost identical in shape and colour to your animal, but lacking a white median line. Your animal is definitely Noumea varians and I now consider Barbara Hanchard's to be Thorunna halourga [see message #22290]- but as I say in her message, the only way 100% sure way to identify this colour group of species is the dissect every specimen, which is an impossible task and rather self-defeating if you are studying their biology.
Best wishes,
Bill Rudman
Noumea varians from Christmas Island
April 15, 2005
From: Dr Michael Seebeck
Does anyone have a clue what this species could be? It is from Christmas Island, Indian Ocean. I have looked in Debelius' book and could not find anything similar. Only about 7mm, but very cute.
Locality: Ryan's Ravine, Christmas Island, Indian Ocean. Depth: 7 m. Length: 7 mm. March 2004. amongst hard corals on rocky bottom. Photographer: Mike Seebeck
Mike Seebeck
michael.seebeck@dotars.gov.cx
Seebeck, M., 2005 (Apr 15) Noumea varians from Christmas Island. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/13447Dear Michael,
This is Noumea varians. It is one of a group of very similarly coloured chromodorids. Have a look at the Noumea purpurea colour group Fact Sheet.
Best wishes,
Bill Rudman
Noumea varians from Okinawa
February 19, 2004
From: Kunihiro Takahashi
Note added 27 Feb 2009: This is probably Thorunna halourga . See message #22290.
Dear Dr.Rudman
I found this slug and two similar ones [message #12158, message #12248] at Okinawa.
Are they Hypselodoris bullocki?
Data
Date: 26 May, 2001
Location: Cape Maeda,Okinawa Japan
Depth: 10m
Length: 8~10mm
W/Temp: 25C degree
Photo by Kunihiro Takahashi
Best Regards,
Kunihiro Takahashi
manta9216@tontonme.ne.jp
Takahashi, K., 2004 (Feb 19) Noumea varians from Okinawa. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/12247Dear Kunihiro,
Although this lacks white marks in the centre of the mantle, I am pretty sure this is Noumea varians. Have a look at the Noumea purpurea colour group Page for a comparison of this group of species.
Best wishes
Bill Rudman
Noumea varians from Reunion Island
October 24, 2002
From: Marina Poddubetskaia
Dear Bill,
I'm just come back from my holidays in Reunion Island and Mauritius (Indian Ocean). I made there many dives and found some interesting guys. I will need your help to identify some beautiful slugs and to confirm my IDs. So, I will begin my contributions to the Forum with this tiny beauty found under a stone in Reunion Island. Is it Noumea varians?
St-Leu, Reunion Island, Indian Ocean. Site: Eboulis Reef. Depth: 12m. Size: 4-5mm, October 10, 2002.
Photo: Marina Poddubetskaia - Nembro website
Best wishes,
Marina.
nembro@nembro.info
Dear Marina,
Thanks for this photo. It is indeed Noumea varians. It is good to get a photo of it so clearly feeding. I have added to 'close-ups' to show the colour pattern and also to show the everted oral tube, a sure sign it is feeding.
Best wishes,
Bill Rudman
Noumea varians from Christmas Island
May 1, 2002
From: W.B. Rudman
Here is a photo of Noumea varians from John Hicks' Christmas Island, Indian Ocean collections.
PHOTO: AM C128199, 12 mm long alive, 29 March 1981, south of Cantilever, on limestone rocks, 8-10m, Christmas Is., Indian Ocean. Photo: John Hicks
Best wishes,
Bill Rudman
Noumea varians from Hawaii
January 19, 2002
From: John Hoover
Dear Bill,
Here is what appears to be a Noumea varians from Hawaii, photographed in the boat channel at Magic Island (Ala Moana) Park, Honolulu a few years ago. As you know, Hans Bertsch and Scott Johnson illustrated a similar animal in their 1981 book, Hawaiian Nudibranchs, calling at the time one of two color forms of Thorunna gloriosa. In a previous posting I believe you identified the other "color form" as Noumea norba. I have not yet seen N. norba here, and to date have seen only this one N. varians. These Noumeas are few and far between, at least in the areas where I dive.
Best wishes,
John
hoover@hml.org
Hoover, J., 2002 (Jan 19) Noumea varians from Hawaii. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/6039Thanks John,
We probably still have some way to go before this Noumea purpurea Colour Group of species is fully sorted out. One character which is quite prominent in your photo is the purple foot. Another character, which is not quite so clear is the colour of the gills - translucent clear with a faint orange border. I can't say that these characters solve it identification for us but they are certainly worth keeping in mind when comparing it with similalry coloured species.
By the way, have you or any of your colleagues in Hawaii made any progress in rediscovering Chromodoris petechialis? It would be wonderful to know that it still exists.
Best wishes,
Bill Rudman
Noumea purpurea? from South Africa
January 29, 2000
From: Valda Fraser
Dear Bill
I think the animal is Noumea purpurea, but I would like you to confirm this.
Locality: South Coast KwaZulu-Natal SOUTH AFRICA. Park Rynie - 25m
Size: 40mm
Date: 28 December 1999
Regards
Valda Fraser
iti04937@mweb.co.za
Fraser, V., 2000 (Jan 29) Noumea purpurea? from South Africa. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/1718Dear Valda,
I am pretty sure this is Noumea varians. If you have a look at the Noumea purpurea colour group page you will see that Noumea varians has quite a distinctive shape with a constriction in the mantle skirt just behind the gills and a wide rounded spatula-like anterior end. Your animal has a complete white median line unlike specimens I have seen from the Pacific but it seems to have two narrow points which equate to the breaks in the line found in Pacific specimens.
Of course only the anatomy will confirm this but my bet would be on Noumea varians.
Best wishes,
Bill Rudman.
Noumea varians from New South Wales
December 18, 1999
From: David & Leanne Atkinson
Hi Bill,
Long time - no hear. The nudis have been pretty quiet over winter and we have been out of the water a lot.
Last weekend at Halifax Park, Port Stephens, New South Wales we found 2 nudis that we had never seen before and can't find them in our books. Unfortunately, we didn't get pictures of the second one.
Attached are 3 pics of one nudi. Any ideas on id ??
David and Leanne Atkinson
atkin@hunterlink.net.au
David and Leanne.
Good to hear from you again and thanks for the photos. They are of Noumea varians which is usually found in much more tropical waters. I have recently posted pages on Noumea varians and some other similarly coloured species.
Best wishes,
Bill Rudman.
