Chromodoris aureomarginata
Cheeseman, 1881
Order: NUDIBRANCHIA
Suborder: DORIDINA
Superfamily: EUDORIDOIDEA
Family: Chromodorididae
DISTRIBUTION
Throughout New Zealand, from intertidal to 20 metres. Not common.
PHOTO
Bradshaw Sound, Fiordland, 15m. 25mm long, 11 May 2005. Photo: Ian Skipworth
The mantle and body are translucent white with a thin bright yellow submarginal band and opaque white marginal band around the mantle. The inner edge of the line is distinct but on the outer side it is more diffuse, merging into the opaque white edge. The opaque white edge is formed from the mantle glands which form a continuous band around the edge of the mantle. The gills, rhinophores are also translucent white. C. aureomarginata is a relatively elongate species and when crawling the foot extends some distance posteriorly beyond the mantle. There are up to eleven simple gills arranged in a circle, open posteriorly, around the anus. The radula is fairly typical for the genus [Radula formula 83.0.83 x 71 (+3) (20mm specimen)], and it one of the species which retains a reduced triangular thickening in the midline.
Originally described by Cheeseman (1881) from the Auckland district, there are records of this species as far south as Stewart Island, but it never common. There are many white species of chromodorid with yellow colouration which I have called the 'C. aureomarginata colour-group'[Rudman, 1985, 1990]. The only similarly coloured species known from New Zealand is Cadlina willani, which differs in having the yellow band at the edge of the mantle, and a yellow median line of the mantle.
Many books on the NZ fauna incorrectly refer to this species as Glossodoris aureomarginata. Odhner (1934) based a new genus and species, Lissodoris mollis, on what I consider to be juveniles of C. aureomarginata [see Rudman, [1984, 1985].
References
• Cheeseman, T.F., 1881. On some new species of nudibranchiate Mollusca. Transactions and Proceedings of the New Zealand Institute, 13: 222-224.
• Eliot, C.N.E., 1907. Nudibranchs from New Zealand and the Falkland Islands. Proceedings of the Malacological Society of London, 7(6): 327-361, Pl.28.
• Morton, J.E.& Miller, M.C., 1968. The New Zealand Sea Shore. Collins, London & Auckland. 638 pages.
• Odhner, N.H. (1924) Papers from Dr. Th. Mortensen's Pacific expedition 1914-16. New Zealand Mollusca. Videnskabelige Meddeleser fra Danske Naturhistorisk Forening, 77: 1-90. (Pls.1-2)
• Powell, A.W.B., 1979. New Zealand Mollusca. Auckland: Collins.
• Rudman, W. B., 1984. The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: A review of the genera. Zoological Journal of the Linnean Society, 81: 115-273.
•Rudman, W.B., 1985. The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: Chromodoris aureomarginata, C. verrieri and C. fidelis colour groups. Zoological Journal of the Linnean Society, 83: 241-299.
• Rudman, W.B. (1990) The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: further species of Glossodoris, Thorunna and the Chromodoris aureomarginata colour group. Zoological Journal of the Linnean Society, 100(3): 263-326.
• Suter, H., 1913. Manual of the New Zealand Mollusca. Wellington: Government Printer.
Rudman, W.B., 2004 (June 21) Chromodoris aureomarginata Cheeseman, 1881. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/chroaureom
Related messages
Chromodoris aureomarginata at Poor Knights
April 26, 2007
From: Ian Skipworth
Hi Bill
Concerning your request for feeding information on Chromodoris aureomarginata: As it happens, I did find C. aureomarginata a few weeks ago on a dive at the Poor Knights. This is the first time I've found this slug at the Knights. The only other occasion I've seen it was in Fiordland.
The attached photos may give some clues as to what the slug feeds on. From memory, it was on the move while I was photographing it.
Location: Bird Rock, Poor Knights Islands, New Zealand. Depth: 12 m. 18 March 2007. Estimated length:15 mm. Photographer: Ian Skipworth
Cheers
Ian
skip@ianskipworth.com
Skipworth, I., 2007 (Apr 26) Chromodoris aureomarginata at Poor Knights. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/19844Dear Ian,
Thanks for the photo. I'm afraid I can't squeeze any feeding info from it - even before cropping the background - but its nice to get another photo of this endemic New Zealander.
Best wishes,
Bill Rudman
Chromodoris aureomarginata from northern New Zealand
April 26, 2007
From: Floor Anthoni
Dear Bill,
Here are some more photos of Chromodoris aureomarginata associated with sponges
Locality: Blue Maomao Arch. Poor Knights Islands, Northland, New Zealand. 25 Dec 2003. Photographer: Floor Anthoni
Dr J Floor Anthoni
http://www.seafriends.org.nz/
floor[at]seafriends.org.nz
Thanks Floor,
As the close-up photo alongside indicates, I am pretty sure the aggregation of nudibranchs here is for mating rather than feeding. In rich substrates like this, it is impossible to be sure if an animal is attracted by a particular species of sponge, unless you actually catch it in the act. In fact most of the organisms here are not sponges - I can see bryozoans, ascidians, hydroids and an encrusting algae. The only sponge I can see is the bright reddish one in the lower right corner. Its possible there is a food sponge nearby but it is most probably in a crevice or partially overgrown.
These photos show the characteristic two-tone submarginal yellow band very well.
Best wishes,
Bill Rudman
Chromodoris aureomarginata feeding
April 26, 2007
From: Dr J. Floor Anthoni
Dear Bill,
Here are some photos of Chromodoris aureomarginata on sponges taken at Parengarenga Harbour in northern New Zealand.
Locality: Paua Wharf, Parengarenga Harbour, Northland, New Zealand. 2 Jan 2004. Photographer: Floor Anthoni.
Dr J Floor Anthoni
floor[at]seafriends.org.nz
Dear Floor,
Thanks for these interesting photos. I have been trying to get information on the feeding of this species for some years without success, and during my short visit to New Zealand I saw a tantalising video clip in the Auckland Museum of this species on a sponge, which revitalised my search. You were one of a number of New Zealand underwater photographers I contacted about this species and Ceratosoma amoena, and your message is one of a number I am posting today from the almost instantaneous response I have received from my request.
The only information I had on C. aureomarginata feeding was a note by Michael C. Miller of it feeding on 'Dysidea fragilis' (see Miller, 1967). Both the photos in your message show it feeding on a species of Dysidea. As this is an unusual sponge for a species of Chromodoris to be eating, it is a very valuable confirmation of Michael Miller's observations from 40 years ago. He also reported C. amoena to feed on Dysidea, and in your lower photo we can see that species as well. [see message #19842 for fuller photos of that species].
The middle left photo is a close-up showing the oral tube everted, which along with the damaged and decolorised sponge alongside, is pretty good evidence of feeding.
- Miller, M. C. (1967) Grazing carnivores - some sea-slugs feeding on sedentary invertebrates. Poirieria (Conchology Section Auckland Institute & Museum), 3(1): 1-11.
Best wishes,
Bill Rudman
Re: Chromodoris aureomarginata from NZ.
June 28, 2004
From: Lindsay Warren
Dear Bill and Ian
Wonderful to have messages back on the site [m12660]. I was, however, rather intrigued to see the date on which this photo was supposedly taken - some 11 months in advance! Interesting example of time travel?! Presume it should have read 11 May 2004.
All the best
Lindsay
alldcl@compuserve.com
Warren, L., 2004 (Jun 28) Re: Chromodoris aureomarginata from NZ.. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/12675Thanks Lindsay,
I must be rusty - have changed it
Cheers
Bill
Chromodoris aureomarginata from Fiordland, NZ.
June 21, 2004
From: Ian Skipworth
Hi Bill
This slug was snapped by me on a recent trip to Fiordland [SW New Zealand]. It has some similarity to what is perhaps a white colour form of Aphelodoris luctuosa already discussed on your site but I suspect it is a different
slug - possibly Chromodoris aureomarginata.
It is about 25mm long and was in about 15m of water. Sorry it's not a great photo. It was taken in Bradshaw Sound, Fiordland, SW New Zealand on 11 May 2004.
Your comments on its identification would be appreciated.
Cheers
Ian Skipworth
Auckland, New Zealand
ian@ianskipworth.com
Skipworth, I., 2004 (Jun 21) Chromodoris aureomarginata from Fiordland, NZ.. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/12660Dear Ian,
This is indeed Chromodoris aureomarginata. It is a nice addition to the Forum as it is one new Zealand species I did not have a good photo of. The submarginal yellow band is very characteristic of this species which is endemic to New Zealand. I have made a new Fact Sheet for this species.
Best wishes
Bill Rudman
