Chromodoris thompsoni
Rudman, 1983

Order: NUDIBRANCHIA
Suborder: DORIDINA
Family: Chromodorididae

PHOTO

UPPER: Twofold Bay, southern New South Wales, March 1986.
LOWER RIGHT: Callala Pt, Jervis Bay, New South Wales, May, 1981.
LOWER LEFT: Quarantine Bch, Sydney Harbour, New South Wales, October 1989.
PHOTOS: Bill Rudman.

There are many red and orange-spotted species of chromodorid in New South Wales and southeastern Australia. I have discussed this example of mimicry on a separate page.

References:
• Rudman, W.B. (1983) The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: Chromodoris splendida, C. aspersa and Hypselodoris placida colour groups. Zoological Journal of the Linnean Society, 78: 105-173.
• Rudman, W.B. (1991) Purpose in Pattern: the evolution of colour in chromodorid nudibranchs. Journal of Molluscan Studies, 57, (T.E. Thompson Memorial Issue): 5-21.

Authorship details
Rudman, W.B., 1999 (June 3) Chromodoris thompsoni Rudman, 1983. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/chrothom

Related messages


Chromodoris thompsoni from Jervis Bay, NSW

October 3, 2005
From: Paul Osmond

Dear Bill,
These three tiny specimens of Chromodoris thompsoni were found on the edge of the open cavern at the 'Spider Cave' dive site in Jervis Bay, NSW, Australia. The blue blotches and the red spots are pretty distinctive.

Locality: Jervis Bay, New South Wales, Australia.Depth: 30 m. Length: 10 mm. 21 August 2005. Rock Wall. Photographer: Paul Osmond

I am guessing that this is the sponge species mentioned in other messages that they are known to eat.
Yours,
Paul

marriard@deepseaimages.com

Osmond, P.T., 2005 (Oct 3) Chromodoris thompsoni from Jervis Bay, NSW. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/14902

Dear Paul,
Thanks for this photo. Although I have recorded this species a number of times on theis speonge, Chelonaplysilla violacea, I haven't got a good photo of it on it as a record. This species can be mistaken for Chromodoris woodwardae, which looks quite like this in one of its colour variants, but in that species the red spot is usually surrounde by a bluish ring while in C. thompsoni the red spot is inevitably placed off-centre in the bluish background spot.
Best wishes,
Bill Rudman

Rudman, W.B., 2005 (Oct 3). Comment on Chromodoris thompsoni from Jervis Bay, NSW by Paul Osmond. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/14902

Chromodoris thompsoni from New South Wales

March 15, 2002
From: Stuart Hutchison


Hi Bill,
Here's Chromodoris thompsoni from Tathra, New South Wales, Australia on 23 Apr 2001. Length 40mm. Depth 8m.

Regards,
Stuart

stuart@stuarthutchison.com.au

Hutchison, S., 2002 (Mar 15) Chromodoris thompsoni from New South Wales. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/6301

Thanks Stuart,
4 cms is quite large for this species, another red-spotted endemic from southeastern Australia. I have just noticed I haven't any dimensions on my photos, I'd better remedy that tomorrow.
Cheers,
Bill Rudman

Rudman, W.B., 2002 (Mar 15). Comment on Chromodoris thompsoni from New South Wales by Stuart Hutchison. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/6301

Chromodoris thompsoni at Shark Point

October 26, 2000
From: Donata P. & Akos L.

Hi Bill,
We think that Chromodoris thompsoni is an easily overlooked species in Sydney owing to its small size perhaps. However, we seem to find them everywhere, from Oak Park to Shark Point quite regularly. I am confident when I say that during every dive we come across several specimens.

Taking a REALLY close look reveals another spectacular species. One of Donata's favourites of course. Location Shark Point, Clovelly around January 1998. [NIKONOS III with a 2:1 xt tube for the extra grunt!]

Regards
Akos & Donata

dna72@softhome.net

Piotrowska, D. & Lumnitzer, A. , 2000 (Oct 26) Chromodoris thompsoni at Shark Point. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/3229

Dear Akos & Donata,
Thanks for the welcome photo. It is a beautiful species, and seems to be endemic (found only in one area) to the New South Wales region of southeastern Australia.
best wishes,
Bill Rudman.

Rudman, W.B., 2000 (Oct 26). Comment on Chromodoris thompsoni at Shark Point by Donata P. & Akos L.. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/3229

Chromodoris thompsoni from sthn New South Wales

December 5, 1999
From: Ron Greer

Dear Bill,

Here is one that my buddy found under the Tathra wharf, southern New South Wales, 26 Nov 99. It is a beautifully marked animal. Although small, (20mm largest seen) they were found in reasonable numbers on seaweed, open sand and algae encrusted rocks.

Your assistance in identification of this nudibranch would be appreciated also.

I hope this information is of use and await your reply.

Regards

Ron Greer

diveimage@i-o.net.au

Greer, R., 1999 (Dec 5) Chromodoris thompsoni from sthn New South Wales. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/1637

Dear Ron,
This is Chromdoris thompsoni, one of the red-spotted species of chromodorid found only in southeastern Australia. It is often quite common in New South Wales, south of Sydney. Although it appears to be crawling all over the place, it is usually not far from a rather nondescript sponge which is apparently its sole food.

Best wishes,
Bill Rudman.

Rudman, W.B., 1999 (Dec 5). Comment on Chromodoris thompsoni from sthn New South Wales by Ron Greer. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/1637