Mexichromis festiva
(Angas, 1864)
Order: NUDIBRANCHIA
Suborder: DORIDINA
Family: Chromodorididae
DISTRIBUTION
Known only from New South Wales and Lord Howe Island, southeastern Australia.
PHOTO
UPPER: North coast, New South Wales, March 1982, with egg ribbon. Note large direct developing eggs.
LOWER: Green Point,Woolgoolga, northern New South Wales, November 1982.
PHOTOS: Bill Rudman.
Mexichromis festiva is apparently endemic to New South Wales, this species has direct development. It is very similar in colour to the more widely spread tropical Mexichromis mariei but the radular teeth of Mexichromis festiva have many more denticles. The reddish-purple spots in Mexichromis festiva are either flat or on a slightly rounded bump, unlike the pointed tubercle which often forms in Mexichromis mariei.
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. (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., 1999 (January 16) Mexichromis festiva (Angas, 1864). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/mexifest
Related messages
Mexichromis festiva from New South Wales
April 16, 2010
From: Sean McMahon
G'day Bill,
I have included a photo of a tiny nudibranch that I am having trouble identifying. I have included the details below I would be grateful if you could shead some light on it.
Locality: Toowoon Bay, The Entrance, Rockpool about 15 cms deep, NSW, Australia, Tasman Sea, Pacific Ocean, 30 October 2009, Pool in ocean rock platform. Length: 11 mm . Photographer: Sean McMahon.
Regards,
Sean.
sean.mcmahon1@defence.gov.au
McMahon, S.P., 2010 (Apr 16) Mexichromis festiva from New South Wales. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/23169Dear Sean,
This is Mexichromis festiva
Best wishes,
Bill Rudman
Mexichromis festiva from sthn Queensland
February 3, 2006
From: Bruce Wilkie
Hi Bill,
Could this little fella be Mexichromis festiva?
Locality: Manta Bommie, Point Lookout, North Stradbroke Island, Queensland, Australia. Depth: 10 metres. Length: 35 mm. 17 December 2005. rocky reef with sponges, hard & soft corals. Photographer: Bruce Wilkie
Many thanks,
Bruce Wilkie.
brucedwilkie@yahoo.com.au
Wilkie, B., 2006 (Feb 3) Mexichromis festiva from sthn Queensland. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/15719Dear Bruce,
Yes this is M. festiva
Best wishes,
Bill Rudman
Mexichromis festiva from Port Stephens, eastn Australia
August 12, 2003
From: Leanne & David Atkinson
Dear Bill,
Over the past 2 summer seasons, 2001-2002 and 2002-2003 we have been finding what we think are Mexichromis festiva at Fly Point, Port Stephens, New South Wales. They are in quite shallow water usually 8m or less, during the day, on the high tide. there has been a slight colour difference from purplish spots rhinophores and gill markings to more of a red. I don't think this is generated by the photography since we take macro shots on the same setting and these slugs are usually around 5 to 8mm. We have also found what we think might be a "one spot " colour variation. What do you think?
Thanks for your help,
Leanne & David Atkinson
atk@hunterlink.net.au
Thanks Leanne & David,
The suggestion that the purple colour can change to wine red is quite interesting. I had initially thought that Mexichromis festiva, which seems to be restricted to eastern Australia had 'wine red' spots, while the more tropical species Mexichromis mariei had purple spots. However the photos we now have on the Forum of these two species, and related species, suggest that the colour may be variable. It would certainly be interesting if we could show the colour can actually change in one individual. I agree your 'one spot' animal is this species
Best wishes,
Bill Rudman
Mexichromis festiva from Heron Island
September 27, 2001
From: Julie Marshall
Dear Bill,
To add to your discussion on the differences between Mexichromis festiva and M. mariei here are photos of two animals from Heron Island [Great Barrier Reef, Queensland]. The reddish purple spots on the mantle are either flat or on a very slightly rounded hump unlike the pointed tubercles on M. mariei. I have found 8 specimens of Mexichromis festiva at Heron Island and all have an almost continuous golden marginal band rather than a band made of golden spots. All animals have been found at the reef crest under dead coral slabs at low tide. The pictured animals were 13 and 15 mm in size.
Best wishes,
Julie Marshall
j.marshall@latrobe.edu.au
Marshall, J., 2001 (Sep 27) Mexichromis festiva from Heron Island. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/5068Thanks Julie,
Yes, despite the continuous yellow-orange border, these look like M. festiva to me. Heron Island, at the extreme southern end of the Great Barrier Reef seems to be the northern limit of a number of so-called New South Wales endemics. (or at least the furthest north we have records of them).
Best wishes,
Bill Rudman
Mexichromis festiva from Sydney
March 17, 2001
From: Erik Schloegl
Dear Bill,
I found this one, which I think is Mexichromis festiva, on rocky reef at a Sydney dive site called "The Colours" (just south of the entrance to Sydney Harbour)[New South Wales, Australia] on 18 February, 2001. The depth was approximately 25m, the water temperature was 22 C.
Best regards,
Erik
Erik.Schlogl@uts.edu.au
Schloegl, E., 2001 (Mar 17) Mexichromis festiva from Sydney. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/3989Dear Erik,
Yes this is Mexichromis festiva. This pretty little chromodorid was first described from Sydney in 1864 by George Angas, who was for a time employed at the Australian Museum. It was one of the first nudibranchs described from Australia.
Best wishes,
Bill Rudman
